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Pectinolytic activity of microorganisms in piling of jute
Abstract
Quantitative as well as qualitative evaluation of microorganisms associated with piling of jute has been studied using raw jute fibre, jute fibre from laboratory bins and fibre samples collected from two jute mills (M/s Bharat Jute Mill and M/s Budge Budge Jute Mill). Bacterial population in raw C. capsularis jute is found to be in the order of 10 4 per gram of jute fibre and that in raw C. oliforius jute is in the order of 10 5 per gram of jute fibre. Bacterial population in laboratory bins is found to be in between 10 6 and 10 7 per gram of jute fibre while fungal population is in between 10 4 and 10 5 per gram of jute fibre. The bacterial isolates are mostly Gram-positive rods of the genus Bacillus and fungi mainly of the genera Aspergillus and occasionally Penicillium. No significant change in strength and fineness of fibre has been observed due to 48 h of piling. Bacterial and fungal populations in piled jute samples of Bharat Jute Mill are found to be in the order of 10 8 and 10 5 per gram of fibre, while the same in Budge Budge Jute Mill are in the order of 10 5 and 10 3 per gram of jute fibre respectively. The bacterial isolates are mostly Gram-positive rods of the genus Bacillus, Gram-positive coccus of the genus Micrococcus and Gram-positive filamentous rods of the genus Streptomyces. Fungal isolates are mainly of the genera Aspergillus and, to a lesser extent, of the genus Penicillium and Dendrophoma. Mucor has been found only in Bharat Jute Mill and Chaetomium is found only in Budge Budge Jute Mill fibre samples. Genera of bacteria and fungi isolated in jute fibre samples from both the jute mills are mostly similar which indicates that only a small group of microorganisms is active in jute bins/piles and they originate from the common source, i.e. soil and water during retting. All the isolated bacteria as well as fungi possess pectinolytic activity. This indicates that the piling microbes might play a significant role in remoling residual pectin from the fibre during piling of jute.
... Some discrete reports are available on investigation of physical, mechanical and other properties of coconut fibre (Bledzki et al., 1996;Stern and Stout, 1954;van Dam et al., 2006;Rahman and Khan, 2007;Coirboard, 2016;NIRJAFT, 1990;Wei and Gu, 2009;Satyanarayan et al., 2007;Brígida et al., 2010;Satyanarayana et al., 1982;Ray and Bandyopadhyay, 1966;Kaswell, 1953;Varma et al., 1984;Meredith, 1945;Banik and Ghosh, 2008), which have been compiled and given in Table 10.2. Similar properties were compared with jute (Satyanarayan et al., 2007;Kaswell, 1953;Mahato et al., 1993) (jute being the highest available lignocellulosic fibre). ...
... 38.3 (Varma et al., 1984;Banik and Ghosh, 2008) 130-220 (Satyanarayan et al., 2007) Young's modulus (Gpa) 4-6 (van Dam et al., 2006;Coirboard, 2016;NIRJAFT, 1990) 0.86-1.94 (Satyanarayan et al., 2007) Work of rupture -0.30 (Mahato et al., 1993) ...
... Cellulose 35-43 (Bledzki et al., 1996;van Dam et al., 2006;Rahman and Khan, 2007;Coirboard, 2016;Brígida et al., 2010;Satyanarayana et al., 1982;Varma et al., 1984;Meredith, 1945) 58-59 (Rahman and Khan, 2007;NIRJAFT, 1990;Meredith, 1945;Banik and Ghosh, 2008) Lignin 40-45 (Bledzki et al., 1996;van Dam et al., 2006;Rahman and Khan, 2007;Coirboard, 2016;Brígida et al., 2010;Satyanarayana et al., 1982;Varma et al., 1984;Meredith, 1945) 12-14 (Rahman and Khan, 2007;NIRJAFT, 1990;Meredith, 1945;Banik and Ghosh, 2008) Hemicellulose 0.15-24 (Bledzki et al., 1996;van Dam et al., 2006;Rahman and Khan, 2007;Coirboard, 2016;Brígida et al., 2010;Varma et al., 1984;Meredith, 1945) 14-25 (Rahman and Khan, 2007;Meredith, 1945;Banik and Ghosh, 2008) Water solubles 5.25 (Coirboard, 2016;Meredith, 1945) -Pectins 3.3-4.0 (Bledzki et al., 1996;Rahman and Khan, 2007;Coirboard, 2016;Varma et al., 1984) 0.2-0.5 (Rahman and Khan, 2007;Banik and Ghosh, 2008) Mineral matter (ash) 2.2 (Bledzki et al., 1996) 0.5-1.2 ...
... Air permeability, abrasion resistance, mass loss, pilling resistance are influenced by the yarn raw material, fibre fineness, yarn linear density, yarn type, yarn tensile properties and hairiness, weave, area density, etc. [24][25][26][27][28][29]. ...
... The results relating to abrasion resistance are shown in Figure 12. Abrasion resistance, mass loss, and pilling resistance are influenced by the yarn's raw material, the yarn's linear density, the weave of the fabric, the area density, etc. [24][25][26][27][28][29]. Abrasion and pilling resistance depend on yarn structure and the spinning method of cotton yarn [25]. ...
The behaviour of textile products made from different fibres during finishing has been investigated by many scientists, but these investigations have usually been performed with cotton or synthetic yarns and fabrics. However, the properties of raw materials such as linen and hemp (other cellulose fibres) and linen/silk (cellulose/protein fibres) have rarely been investigated. The aim of the study was to investigate and compare the mechanical (breaking force and elongation at break) and end-use (colour fastness to artificial light, area density, and abrasion resistance) properties of cellulose and cellulose/protein woven fabrics. For all fabrics, DE was smaller than three, which is generally imperceptible to the human eye. Flax demonstrated the best dyeability, and hemp demonstrated the poorest dyeability, comparing all the tested fabrics. The colour properties of fabrics were greatly influenced by the washing procedure, and even different fabric components of different weaves lost their colours in different ways. Flax fibres were more crystalline than hemp, and those fibres were more amorphous, which decreased the crystallinity index of flax in flax/silk blended fabric. Unwashed flax fabric was more resistant to artificial light than flax/silk or hemp fabrics. Finishing had a great influence on the abrasion resistance of fabrics. The yarn fibre composition and the finishing process for fabrics both influenced the mechanical (breaking force and elongation at break) and end-use (area density and abrasion resistance) properties of grey and finished fabrics woven from yarns made of different fibres.
... Besides selection of covering material and deepness of layers of jute bundles are considered to be critical factor to get quality fiber (Kundu, 1956). During retting, the cementing materials i.e. pectins, hemicelluloses and proteins of stem are consumed by the aquatic microoagnism (Banik and Ghosh, 2008). Thereafter, these bundles are taken out from the water to extract the fiber manually from the retted stem (Sarkar and Sengupta, 2015). ...
... Micro-aerophillic/anerobic bacteria is entered into the tissues to decompose the cementing materials (mostly pectin) connecting the fiber strands with release of galacturonic acid and sugar in retting water (Basak et al., 1998;Banik and Ghosh, 2008). The greater part of decomposition during retting was performed by anaerobic microorganisms. ...
Microbial community structure throughout the jute retting period. Structure of the microbial community showed diverse genera and species throughout the whole retting period of jute. Mainly firmicutes and proteobacteria involved maximally in retting process. Various physical, chemical and biological factors were determined the effective retting process viz temperature, moisture, sugar content, pectin, cellulose like other polysaccharide content etc.
... Application of mixed enzyme (Cellulase, Xylanase and Pectinase) on jute shown significant positive changes on physical characteristics of jute fibers in terms of whiteness index, brightness index (Vigneswaran and Jayapriya, 2009). Until now there were several attempts that has been taken to test the pectinolytic activity of microorganisms like fungi (Haque et al.,2001b), bacteria (Das et al., 2012a) for retting and pilling of jute (Banik and Ghosh, 2008) and identified through technique like 16S rDNA analysis (Das et al., 2012a;Das et al., 2011;Munshi and Chattoo, 2008) or through Bergey's manual (Banik and Ghosh, 2008;Ali, 1958;Jalaluddin, 1965) and assessment of bacterial community done through biolog ecoplates under different stages of jute retting at different location (Das et al., 2013). Until now there is no report available on the identification of retting microorganisms through using BIOLOG Microplate system from retting water. ...
... Application of mixed enzyme (Cellulase, Xylanase and Pectinase) on jute shown significant positive changes on physical characteristics of jute fibers in terms of whiteness index, brightness index (Vigneswaran and Jayapriya, 2009). Until now there were several attempts that has been taken to test the pectinolytic activity of microorganisms like fungi (Haque et al.,2001b), bacteria (Das et al., 2012a) for retting and pilling of jute (Banik and Ghosh, 2008) and identified through technique like 16S rDNA analysis (Das et al., 2012a;Das et al., 2011;Munshi and Chattoo, 2008) or through Bergey's manual (Banik and Ghosh, 2008;Ali, 1958;Jalaluddin, 1965) and assessment of bacterial community done through biolog ecoplates under different stages of jute retting at different location (Das et al., 2013). Until now there is no report available on the identification of retting microorganisms through using BIOLOG Microplate system from retting water. ...
Jute is considered as one of the cheapest natural fibre after cotton in terms of its production and uses. Retting is the most important post-harvest operation to yield high quality jute fibre and is solely carried out by various types of retting microorganisms. The present study was undertaken to screen and characterize the efficient retting microbes isolated from retting water based on their enzymatic activity followed by biolog based idenfication of those efficient microbes. These isolates were characterized on the basis of qualitative and quantitative estimation of Pectinolytic, Xylanase and Cellulase activity. Out of 40 isolated strains only 3 were finally identified as efficient jute retting microorganism having high pectinolytic and Xylanase activity coupled with less Cellulase activity. These identified three micro organisms may provide a suitable means to develop a new retting technique especially under water stress condition.
... According to Banik & Ghosh (2008), pectinase enzymes can basically be produced naturally using bacteria or fungi. The pectinase enzyme can be produced through the isolation of Bacillus sp and Streptomyces sp bacteria and the isolation of Aspergillus sp and Penicillium sp. ...
This study aimed to determine the effect of various concentrations of Penicillium chrysogenum isolates on the production of pectinase enzymes from pineapple peel waste. The experiment was arranged in CRD (completely randomized design) with six different isolate concentrations (4%; 8%; 14%; 16%; 20%; and 24%). The experiment constituted of three stages, namely production of enzymes by using Penicillium chrysogenum isolates, enzyme harvesting with a goal to obtain a crude extract of the enzymes, and enzyme characterization. Parameters in this study included enzyme activity, optimum temperature, optimum pH, Km value, and Vmax value. Results showed that the highest yield (1.87 g) was obtained from the 24% treatment and the lowest in the 4% treatment at 1.63 g. The highest enzyme activity in the 24% treatment was 1.924 U/ml and the lowest was in the 4% treatment, namely 0.949 U/ml. The highest Vmax value was 0.690 U/ml from the 24% treatment and the lowest was 474 from the 4% treatment. Conversely, the highest Km (0.040 mg/ml) value was found in 4% treatment and the lowest (0.016 mg/ml) was observed in 24% treatment. Keywords: Characteristics, Enzyme, Fungi, Pectinase, Pineapple
... That biopreparation had the capability for retting of flex using EDTA at higher pH, being mono-component, low cost, and commercial accessibility signifies its importance. Pectinolytic microorganisms are also utilized in jute fibers piling in Jute Mills to upgrade their elasticity and manufacturing superior class yarns (Banik & Ghosh, 2008). ...
Pectinolytic enzymes belonging to the hydrolases class of enzymes are one of the enzymes of central importance in biotechnology with approximately 25% global contribution in the food and beverage enzyme industry. They possess the most prominent position among all the commercially produced industrial biocatalysts. These biocatalysts are an indispensable part of sustainable environment as well as an environmentally friendly tool of nature with broad application perspective in many industrial procedures, such as retting and degumming of plant fibers, fermentation of tea and coffee, oil extraction, clarification of fruit juices and wine, valorization of industrial wastes, debasement of cellulosic biomass for biofuel production, wastewater remediation, desizing, scouring and bleaching of fabric, animal feed production, and protoplast fusion technology, etc. Similar to many other industrial-grade enzymes, pectinases also face the limitation of low production yield and productivity in its economized production. Therefore pectinases have been the subject of studies aiming to achieve high production levels on a profitable commercial scale. Natural sources of pectinases are frequently preferred because of ease of extraction and production, so pectinases extracted from microbial cultures are employed more frequently at commercial scale frequently owing to their ease of production and unique physicochemical properties. This chapter mainly emphasizes the production of pectinase enzymes along with a brief overview of different types of recent tactics and plans used for the optimization of various production mediums to get overexpression/production and as well as its application in various industrial sectors.
... Most of the water-based microbiological retting process mostly involves bacteria along with various fungi, protozoa, algae, and diatoms (Tamburini et al., 2003). Aerobic/microaerophilic microorganisms entered into the tissues to decompose the cementing materials such as pectin connecting the fiber strands and release of galacturonic acid and sugar in retting water (Basak et al., 1998;Banik and Ghosh, 2008 (Chakravarty et al., 1962: Ahmed, 1963. After retting over the retting water was characterized and the structure of microbes was identified which showed the aerobic microorganisms like Bacillus, Aspergillus, and Mucor were found dominant. ...
It is expected that this training manual shall prove usefulness to different stakeholders closely working with farming community to impart basic and advanced knowledge on quality improvement and grading
... This green enzymatic process prevents the use of the hot alkaline solution, high energy consumption, and environmental pollution (Singh et al. 2020). In addition to this, pectinases improve the malleability and good separation of blast fiber from decorticated ramie fiber, producing better quality yarn (Banik and Ghosh 2008). ...
Pectinase, a group of pectin degrading enzymes, is one of the most influential industrial enzymes, helpful in producing a wide variety of products with good qualities. These enzymes are biocatalysts and are highly specific, non-toxic, sustainable, and eco-friendly. Consequently, both pectin and pectinase are crucially essential biomolecules with extensive applicatory perception in the biotechnological sector. The market demand and application of pectinases in new sectors are continuously increasing. However, due to the high cost of the substrate used for the growth of microbes, the production of pectinase using microorganisms is limited. Therefore, low-cost or no-cost substrates, such as various agricultural biomasses, are emphasized in producing pectinases. The importance and implications of pectinases are rising in diverse areas, including bioethanol production, extraction of DNA, and protoplast isolation from a plant. Therefore, this review briefly describes the structure of pectin, types and source of pectinases, substrates and strategies used for pectinases production, and emphasizes diverse potential applications of pectinases. The review also has included a list of pectinases producing microbes and alternative substrates for commercial production of pectinase applicable in pectinase-based industrial technology.
Key points
• Pectinase applications are continuously expanding.• Organic wastes can be used as low-cost sources of pectin.• Utilization of wastes helps to reduce pollution.
... The convenience of microbes results in the decline of fiber damage, energy consumption, and non-toxic effluents. Banik et al. (2008) put forward the exploitation of pectinolytic microbes in the piling of jute fibers and their ability to enhance yarn quality. The propensity of pectinases in the breakdown of complex molecules, retting, and degumming of fiber crops are remarkable (Chiliveri et al., 2016). ...
Global fiber production contributes 107 million MT in 2018 and is expected to grow 145 million MT by 2030. Fiber production can be plant-based, animal-based, man-made, and synthetic fibers. Plant-based fibers include jute, ramie, and hemp, have a market share of 5.7% in textile industries. The emerging interest in plant-based fibers, agricultural residues could be addressed by adopting unexplored plant fibers. Textile processing of natural fiber necessitates the removal of the hemicellulosic substance. The major concern of this investigation is the degumming of natural fibers by an eco-friendly method. The ideology is focused on producing hemicellulose degrading enzymes through solid substrate fermentation and utilization of hemicellulose degrading enzymes in natural fiber degumming. Degumming of fiber can be performed by hemicellulose degrading enzymes such as Pectinase, Xylanase, and Laccases. The neglection of the non-cellulosic layer corresponds to an increase in tensile strength, crystallinity, fineness, removal of non-cellulosic substances. The degummed fiber has remarkable applications in fabrication, cutlery application, and textile industries. Our investigation enclosed consolidated reports on the agricultural residues for hemicellulose degrading enzyme production and application of enzymes for natural fiber degumming proclaimed in recent years. The practical difficulties in adopting degummed fibers in textile industries have also been discussed.
... The Ramie gum composed of cellulose, hemicellulose, lignin and pectin is a rich carbon source [3] which is usually discarded after degumming, contaminating the environment. These gum constituents are reported to be utilized by bacteria [7,12,2] provided they would break down these constituents into simpler form. With this background knowledge we attempted to utilize the Ramie gum as a feed for bacteria with an objective to minimize cost as well as environmental damages. ...
... The constituents of coconut fibre and jute [25] are given in Table 1. The constituent analysis unveil the presence of cellulose (38%) and lignin (32%) in almost equal proportion in fibre composition followed by hemicelluloses (25%), pectin (0.5%), ash (1.6%) fat and waxy substances (1.1%) for coconut fibre. ...
Structure and physico-mechanical properties of Cocos nucifera L. fibre from a specific agro-climatic region of India, was thoroughly studied. Fine structure of the fibre was examined by Fourier Transform Infra-Red (FTIR) spectroscopy, Thermo-Gravimetric Analysis (TGA), X-Ray Diffraction (XRD), component analysis, Scanning Electron Microscope (SEM) and optical microscope. SEM shows prominent longitudinal cracks and micro-pores on the surface. XRD shows a low degree of crystallinity (45%), bigger crystallite size, and even the presence of appreciable amount of non-cellulose matter. FTIR reveals presence of large quantities of hydroxyl, phenolic and aldehyde groups. Component and thermal analyses indicates presence of cellulose and lignin as major components. Physical parameters reveal that, fibres are highly variable in length (range 44–305 mm), and diameter (range 100–795 µm). Mechanical properties of the fibre viz. breaking tenacity, breaking extensibility, specific work of rupture, and coefficient of friction were measured. Microbial decomposition test under soil reveals excellent durability of coconut fibre which makes it appropriate for the application in geotextiles. Mass specific electrical resistance of 4 Ω-kg/m2 indicates its enhanced insulation as compared to the jute.
... Bioprep has ability to ret flax with EDTA at high pH, being monocomponent in nature, low price and due to commercial availability it is potentially very important. Pectinolytic microbes are also exploited in piling of jute fibers by Jute Mills for improving their pliability and producing better quality yarn (Banik and Ghosh, 2008). ...
Pectinolytic microbes have been industrially exploited for pectinases that are environment friendly enzymes and mineralize pectic substances present in the environment. This review provides structural understanding of the molecular determinants of pectin utilization, mechanisms driving catabolite selectivity and industrial applicability. The topology of pectinase with distinct catalytic machinery enables it to persist in harsh environment during infection and analysis of pectin degradation pathway has resulted in understanding the role of different pectinases in subsequent steps of substrate digestion in different cellular compartments. The pH has a definite role in altering enzyme properties. Acidic pectinases are utilized especially in food processing industries for extraction and clarification of fruit juices. Alkaline pectinases find tremendous applications in biotechnology based industries especially for cotton bioscouring and retting of plant fibers in textile processing, paper making and treatment of waste water containing pectinaceous material.
This study aims to determine the effect of treatment concentrations (4%; 8%; 10%; 13%; 16%; 20%) of Bacillus subtilis bacterial isolates on the production of pectinase enzymes from pineapple peel waste, and the characteristics of the pectinase enzyme produced include (enzyme activity, optimum temperature, optimum pH, Km and Vmax values). The yield of crude enzyme extract production from the 6 treatments carried out, the highest yield was found in the 10% treatment at 1.59 g and the lowest in the 4% treatment at 1.53 g. In the results of enzyme characterization, the highest enzyme activity was found at a concentration of 20% at 1.883, and the pectinase enzyme produced was able to work optimally in environmental conditions with a temperature of 400C and pH 4 at all concentrations, but the highest activity at variations in temperature and pH was on enzymes with 20% bacterial concentration treatment, namely 0.680 at 400C and 0.650 at pH 4. Enzyme kinetics analysis obtained from the pectinase enzyme produced, showed the highest Km value of 0.021 at a concentration of 4% while the lowest value is 0.0095 at a concentration of 20%. Then at the Vmax value of the enzyme, the highest value was found at the 20% concentration treatment and the lowest value was at 4% treatment was 0.481.Keywords: Bacillus subtilis, Characterization, Enzyme Production, PektinaseEnzyme
The aim of this research was to analyse the influence of fancy yarn structure on the abrasion
resistance and air permeability of woven fabrics with these yarns. The dependencies of
end-use properties and such fancy yarn structures as slub, loop or spiral were analysed.
The influence of the fancy yarn structure, raw material and fabric weave on the abovementioned properties of fabrics with fancy yarns was established during the investigation. Abrasion resistance is the fabric’s ability to not change its strength and appearance during
friction. The air permeability of outerwear is very important in wear comfort and durability.
It was estimated that the parameters of yarns and fabric mentioned above influence the enduse properties of fabrics with fancy yarns.
A pilot-scale and demonstration enzyme plant was set up at Islam Jute Mills, Mirzapur, Bangladesh. A. terreus, was used to produce 200 litres of enzyme per day with 50 kg wheat bran used as the substrate. The biochemical composition of the enzymes produced was exocellulase 0.39 IU/mL, endocellulase 0.4 IU/mL, β-glucosiclase 0.02 IU/mL, endoxylanase 1.01 IU/mL, β- xylosidase 0.09 IU/mL, exopolyglacturonase 0.39 IU/mL, endopolyglacturonase 1.06 IU/mL and pectinlyase 0.52 IU/mL. The optimum temperature and moisture content for the enzyme production were 32°C and 50 parts water added to 100 parts of substrate, respectively. Enzymes were applied to different grades of jute in five jute mills in Bangladesh. Results showed that physical properties such as fibre fineness, brightness, strength, and yarn regularity improved significantly. The improvement in fibre qualities made it possible to use enzyme-treated low-grade fibres successfully in different proportions to replace fibres of higher grade without impairing the production efficiency and the quality of yarns. Due to the application of enzymes, the batch cost of raw materials was reduced by US$ 7-35 per tonne, the actual amount depending upon the batch composition for different products.
With the preponderance of low-grade jute and mesta fibres available to the industry, softening of the barky and hard root-ends has become a major need in the batching section of a jute mill. The enzymatic method, developed earlier at the Indian Jute Industries' Research Association to soften and clean the body of low-grade lignocellulosic fibres, has been utilized for the purpose, with some modifications, for the release of adequately clean and split filaments of normal jute. Test results obtained from bulk trials in mills show that enzymatic softening of root-ends leads to the double benefit of using a higher proportion of root-section fibre in the batch and improved performance of the process, especially at the spinning stage. Except for the low-grade white jute (Grade W5 and below), all other root-end-treated low-grade fibres could be processed without cutting the root-ends and incorporated in higher proportions in the hessian- and sacking-warp batches without any difficulty in spinning. When the root-end treatment was extended to cover all the piled fibres, especially of the low-grade type, the spinning performance of the sacking-weft batch, mainly consisting of soft fibres released from pre-treated line cuttings, was significantly improved. The estimated net cost-saving realized from this enzymatic process, including gains from improved performance in spinning, ranged from Rs 50/- to Rs 100/- (i.e., from about £2.75 to £5.50) per tonne of batch.
The instrument is based on the simple principle of counting the hairs at a fixed distance from the yarn body. For this purpose, the yarn is passed at a constant speed over a guide that holds the axis of the yarn perpendicular to a parallel beam of light falling upon a sensor. As the yarn passes over the guide, the protruded fibres momentarily interrupt the light beam, which can be detected by a silicon photo-transistor, the sensor. The number of such protruding fibres in a particular length of yarn can thus be counted.
Jute—an important cash crop of eastern India is traditionally grown for extraction of fibre by a natural microbial process known as retting. Usually mature stems of harvested jute plants are allowed to ret in pond or ditch water. Retting is a preferential rotting process to separate the fibre from woody stem without damaging the fibre cellulose. Retting microbes consume the non-fibrous cementing materials mainly pectin and hemicellulose. Over retting causes degradation of fibre cellulose while under retting causes incomplete removal of gummy materials viz., pectic substances. Both over retting and under retting which are very difficult to control causes production of low grade jute fibre. In conventional retting, a huge biomass undergoes decomposition in stagnant water, so retting causes environmental pollution. In ribbon retting, ribbons are stripped out mechanically from the stem of mature jute plants, coiled and allowed to ret under water. Ribbon retting reduces time of normal retting by 4–5 days. Moreover, requirement of water for ribbon retting is almost half in comparison to conventional whole plant retting under normal condition. This also reduces environmental pollution to a great extent. But use of efficient pectinolytic microbial inoculum improves quality of fibre, further reduce the time of retting and the environmental pollution. In our study, a mixed bacterial retting culture, developed in our institute, was inoculated during ribbon retting of jute. The ribbon retted jute fibres are absolutely free from bark and were of higher grade. Moreover, the fibre filaments were stronger, improved coloured and finer textured compared to conventional stem retted jute fibres. Most of the defects arising from conventional retting could be overcome by ribbon retting. So, ribbon retting is a great promise to produce high quality jute fibre in one hand and a more eco-friendly measure on the other.
Eight bacteria, each of the genus Bacillus, two actinomycetes, each of the genus Streptomyces, and six fungi, one each of the genus Penicillium and Chaetomium and four of the genus Aspergillus, were isolated on AlPO4-sucrose agar from a typical Indian lateritic soil (Typic Ochragualf). All of them were capable of solubilizing Ca3(PO4)2 to a higher degree than AlPO4. Bacillus subtilis (B-7655), LAB4, Bacillus sp., LAB5, Penicillium sp., LAF2, and Aspergillus spp., LAF3 and LAF4, were solubilizing Ca3(PO4)2 very efficiently, but AlPO4 to a lesser degree. Bacillus spp., LAB1, LAB2, LAB5, LAB6 and LAB7, Chaetomium nigricolor, LAF1, and Aspergillus spp., LAF5 and LAF6, were unable to bring detectable amounts of soluble phosphorus to solution from AlPO4. Except Chaetomium, all the other organisms produced free aliphatic organic acid in detectable amounts. The organic acids produced were oxalic, succinic, citric, and 2-keto gluconic acid. 2-Keto gluconic acid, singly and in combination with succinic or citric acid, accounted for higher solubilization. Amount of free organic acids in the growth medium was not directly correlated with phosphate solubilization.