Vivek Rangarajan

• MTech, Ph. D
• Professor (Associate) at Birla Institute of Technology and Science, Pilani - Goa Campus

The present study focuses on formulating a stable green oil-in-water nanoemulsion (NE) formulation for pesticide application, thereby addressing the primary challenges of botanical pesticides by improving the stability, efficacy, and wettability of leaf surfaces. Neem oil and rhamnolipid biosurfactant were utilized as the base oil and surfactant, r...

Food preservation and fortification pose significant challenges in the fruit and dairy sectors, particularly in developing regions with limited infrastructure and rising production volumes. Cashew apples, rich in antioxidants such as vitamin C and polyphenolic compounds, often go to waste due to their high perishability. In Goa, India, these discar...

Purpose Cashew Apple Juice (CAJ), rich in reducing sugars, is used to make a Geographical Indication alcoholic beverage named “Feni,” with a unique aroma. However, the alcohol yield from the reducing sugar (YP/S) of CAJ has been assessed to be as low as 0.24 g/g against the theoretical yield of 0.51 g/g. This poor yield of alcohol is mainly attribu...

As lead molecules, cyclic lipopeptides with antibacterial, antifungal, and antiviral properties have garnered a lot of attention in recent years. Because of their potential, cyclic lipopeptides have earned recognition as a significant class of antimicrobial compounds with applications in pharmacology and biotechnology. These lipopeptides, often wit...

The surge in global biofuel demand is propelled by intensifying concerns over climate change and effective waste management. Government mandates on biofuel blending further boost this trend, underlining the significance of selecting renewable feedstocks, such as bioethanol and biodiesel, for biofuel production. The importance of selecting an effici...

Nanoemulsions are colloidal systems characterized by tiny droplet sizes with increased kinetic stability. Due to their exceptional properties, nanoemulsions find applications in cosmetics, drug delivery, and food industry. Nanoemulsions can encapsulate bioactive compounds and distribute them efficiently for specific purposes. In the current work, w...

Extractive fermentation is a potential process intensification integrated with aqueous two-phase extraction for simultaneous in-situ product recovery during fermentation to improve the efficiency of any bioprocess industry. This minimizes the innate product inhibitions, recovery, operational issues, and sustainability during conventional fermentati...

The cashew tree (Anacardium occidentale), which originated in Brazil but is now grown in many countries, including India, goes by the common name of the cashew nut. In addition to being a delectable snack in many areas of the world, cashew nuts are also rich in protein, fiber, and minerals, including iron, magnesium, and zinc. The cashew nut develo...

The increasing demand for biopolymers across diverse fields, such as food, medicine, cosmetics, and environmental applications, has prompted researchers to explore novel molecules with enhanced functionalities that meet these demands. In this study, a thermophilic strain of Bacillus licheniformis was employed to produce a unique polyamino acid. Thi...

Global water scarcity and water pollution necessitate wastewater reclamation for further use. As an alternative to conventional techniques, membrane technology is extensively used as an advanced method for water purification and wastewater treatment due to its selectivity, permeability, and efficient removal of pollutants. However, microbial biofou...

This study examines the structural compatibility of various combinations of structurally diverse biosurfactants, saponin, a biosurfactant (derived from plants), and rhamnolipid and surfactin, biosurfactants derived from microorganisms) in the formulation of stable oil-in-water (O/W) nanoemulsion using the high-energy ultrasonication technique, and...

The application of on-site produced cellulolytic enzymes in place of commercial enzymes towards hydrolytic preparations of reducing sugars using inexpensive lignocellulosic wastes is considered the most efficient strategy to accomplish a cost-effective biofuel production process. Along with improved production, intrinsic and systematic performance...

A membrane-based approach for the selective concentration of therapeutic cocosin from coconut milk whey was reported in the present investigation. A high-performance polyether sulfone (PES) based affinity membrane with natural deep eutectic solvent as an adjuvant was prepared and characterized by scanning electron microscopy. It was observed from t...

Anthropogenic CO2 emitted by burning fossil fuels have been the most prevalent cause of global warming. Recent investigations on the use of liquid scrubbers as absorbents have been carried out widely. In the current study, the ability of protic deep eutectic solvents (pNADES) to act as liquid scrubbers is being investigated. Sixteen pNADESs formed...

Plant diseases need to be controlled as they hamper the ecosystem by affecting the quality and availability of food, feed, crops, and fiber produced by plants and farmers worldwide. Different methods and approaches are unraveled to prevent and control plant diseases. In agricultural practice, fungal diseases are the most common crop-devastating dis...

Bacillus lipopeptides are promising biosurfactants that find applications in various sectors like biotechnological, cosmetics and biopharma due to their outstanding functionality like high specificity, low toxicity, and high surface activity. Among the different Bacillus species, Bacillus subtilis is well known for producing a biosurfactant surfact...

The ample interesting properties of lipopeptide biosurfactants- to name a few- hemolytic, antiviral, antifungal, and antibacterial properties are of significant interest to the research community. Surfactin, one of the most potent microbial surfactants, is a biosurfactant of the lipopeptide type with interesting physicochemical characteristics and...

Since the earliest days, occurrence of deadly outbreaks caused by prevalence of different pathogenic virus infections affected human community periodically and caused millions of deaths per year. In order to improve safety and quality of human life against virus infections, it is imperative to do rigorous evaluation of existing virus treatment or e...

Oleaginous yeasts, capable of accumulating a substantial amount of triglycerides, have immense potential to serve as a sustainable feedstock for biodiesel production. However, the techno-economic challenges currently associated with the commercialization of the biodiesel production process prompt for a significant improvement in the cultivation met...

A systematic evaluation of microorganism’s potential towards biosynthesis of cellulases from inexpensive lignocellulosic feedstock through appropriate kinetic modelling facilitates understanding, optimization and designing of an effective industrial cellulase enzyme production process. The present study aims to optimize a submerged fungal cultivati...

The current work aims to formulate a stable cosmetic nanoemulsion using nature-derived ingredients such as surfactin (a lipopeptide-type biosurfactant produced by Bacillus sp) as an emulsifier, plant-based essential oil as a bioactive ingredient, and coconut oil as the base oil using high-energy ultrasonication method. To accomplish a stable nanoem...

Cellulolytic enzymes play the most indispensable and centralized role in the hydrolysis of cellulosic material. Effective enzymatic hydrolysis is one of the major prerequisites in the development of a successful lignocellulosic biorefinery. However, the high cost of cellulase production yet remains to be the major bottleneck for large-scale commerc...

Nanoemulsions are being increasingly utilized in the pharmaceutical, cosmetics, and food industries. They have gained special attention in the cosmetic sector owing to their smaller size and higher kinetic stability and their ability to improve the cutaneous penetration of active ingredients. In addition, they reduce transepidermal water loss, whic...

Cashew farming- considered as one of the major profit-making agricultural businesses- requires renewed practices in processing its products and by-products for sustained growth. The current review highlights the commercial potential of cashew apples by proposing value-addition strategies through microbial fermentation routes that can help garnering...

Postharvest diseases caused by fungal phytopathogens account for about 44% of global fruit and vegetable losses. Biocontrol strategies for postharvest disease are particularly attractive as they are environmentally benign and non-toxic. Current biocontrol strategies employ microorganisms as the biocontrol agents, with application under controlled e...

Crude oil is a major energy source that is exploited globally to achieve economic growth. To meet the growing demands for oil, in an environment of stringent environmental regulations and economic and technical pressure, industries have been required to develop novel oil salvaging techniques. The remaining ~70% of the world’s conventional oil (one-...

The current study investigated an integrated fermentation process for efficient conversion of pulp and paper sludge (PPS) material to bio-ethanol. To achieve maximum yield of reducing sugar from the pretreated PPS, most influencing parameters such as enzyme dosages, surfactant dosages on PPS loadings were optimized in a batch saccharification proce...

The present study is an attempt to throw insight into the significance of the type of nitrogen sources and their uptake pattern on the kinetics of surfactin production by Bacillus subtilis MTCC 2415. Batch kinetics studies revealed that surfactin production was strongly influenced by nitrate ions than ammonium ions. A maximum surfactin concentratio...

Consumers of face-care cosmetics have been continuously evolving and are more receptive to skin-care products that integrate both health and wellness. This subsequently prompted cosmetic manufacturers to renew their formulation approaches by allowing gradual replacement of synthetic ingredients with promising natural alternatives. Among various ava...

The Bacillus surfactin lipopeptides, widely used as potent biosurfactants, have been increasingly researched for diverse applications, necessitating quantification during the production and purification stages. Lipopeptides are typically quantified by Reversed Phase-High- Performance Liquid Chromatography and High Performance Thin Layer Chromatogra...

In the current study, the use citrus peels as the lignocellulosic feedstock for the production of reducing sugars and hydrolytic enzymes was evaluated. Citrus peels were subjected to a two-step pre-treatment procedure to obtain two major fractions-the water soluble pectin rich fraction and the water insoluble solid fraction enriched with cellulose...

Lignocellulosic-biomass is currently being used as the potential feedstock for bioethanol production. Various feed-stocks such as wood, grass, agricultural wastes obtained post- the- harvest have been the popular choices and hence being increasingly researched for bioethanol production. However, the research focus on the use of fruit wastes as feed...

This study demonstrates the use of Bacillus lipopeptides as both capping and stabilizing agents in the single-step synthesis of silver nanoparticles (Ag-NPs). With the aim to achieve a stable Ag-NP suspension, two methods of synthesis procedures, methods A and B, were tested and compared. In method A, the excess reactant sodium borohydride (NaBH4)...

Biosurfactants are powerful surface active agents synthesized essentially by microbes. They have interesting properties such as biodegradability, less toxicity and stability at extremes of pH, temperature and salinity. Their diverse structures along with superior properties qualify them as potential candidates for application in food, cosmetic, pha...

The results from this study have chemistry and engineering implications of surfactin molecules in sustainable synthesis of microemulsions and microbubbles.

Experimental investigations were carried out for Cupriavidus necator (MTCC 1472)-based improved production of poly-3 hydroxy butyrate (PHB) through induced nitrogen limiting fed-batch cultivation strategies. Initially Plackett–Burman design and response surface methodology were implemented to optimize most influencing process parameters. With optim...

A lipopeptide biosurfactant produced by marine Bacillus megaterium and a biopolymer produced by thermophilic Bacillus licheniformis were tested for their application potential in the enhanced oil recovery. The crude biosurfactant obtained after acid precipitation effectively reduced the surface tension of deionized water from 70.5 to 28.25 mN/m and...

Lipopeptides are green surfactants with myriad applications in the areas of healthcare, energy and environment. However, the commercial potential of these ecofriendly molecules could not be fully realized due to lack of an economically viable and environmentally sustainable purification process. Thus, we endeavored to systematically develop and sca...

The growing interest in Bacillus lipopeptides for high-value applications has driven process design, development and optimization for enhanced lipopeptide production. Traditional optimization approaches have been directed towards improving the overall titres by modification of media components and environmental parameters, almost exclusively in sub...

Polymeric nanocomposites embedded with nontoxic antimicrobial agents have recently gained potential industrial significance, mainly for their applicability to preserve food quality and ensure safety. In this study, a poly(butylene adipate-co-terephthalate) (PBAT)/organoclay (CMMT) based nanocomposite film doped with sodium benzoate (SB) as antimicr...

Poly(butylene adipate-co-terephthalate) (PBAT) nanocomposites films are prepared by a solution intercalation process using natural montmorillonite (MMT) and cetyltrimethylammonium bromide (CTAB)-modified montmorillonite (CMMT). Cation exchange technique has been used for modification of MMT by CTAB and characterized by Fourier transform infrared...

Objective: The present research focused on the production and process optimization of pectinase using orange peel as substrate by solid state fermentation. Methods: Orange peel, a major by product from fruit processing industry has been used to formulate a prescribed liquid medium named as Enriched Pectin Extract Medium (EPEM) for enhanced product...

Biosurfactants have recently emerged as promising molecules for their structural novelty, versatility, and diverse properties that are potentially useful for many therapeutic applications. Mainly due to their surface activity, these molecules interact with cell membranes of several organisms and/or with the surrounding environments, and thus can be...

Microbial biosurfactants produce foam during aerobic-fermentation processes. The degree of foaminess and foam stability of the lipopeptide-biosurfactant produced by a marine Bacillus megaterium strain were investigated using simulated biosurfactant solution (SBS), biosurfactant broth without cells (BBWOC) and biosurfactant broth with cells (BBWC) i...

Abstract BACKGROUND: Lipopeptide production is strongly influenced by trace metals. The availability of free Fe2+ in the media throughout the process of fermentation was found to be very critical. Since free Fe2+ was reported to be sequestered by the lipopeptide as it was produced, intermittent feeding of Fe2+ was strategized and optimized for enha...

in a semi- defined medium. Firstly, the carbon and nitrogen sources were optimized at shaker flasks level. Glucose at 30 g/l and yeast extract at 5 g/l were found to be the optimum concentrations, yielding 4.2 g/l Xanthan. Subsequently, the process conditions (pH, agitation rate and aeration rate) were optimized using Response Surface Methodology (...

Hyaluronidase was produced by submerged fermentation from Streptococcus mitis. The possibility of using Streptococcus mitis for enzyme production has been recently investigated. In this study, the physical and nutritional parameters were optimized to improve the production of hyaluronidase by Streptococcus mitis and it was accessed. Maximum prod...

Orange peel solids (OPS) and orange peel extract (OPE) were used as the substrates for pectinase production from Aspergillus niger. Among the various nitrogen sources (organic and inorganic) tested highest yield of pectinase production was observed for peptone as the nitrogen source in submerged fermentation using OPE and soybean meal as the nitrog...

Oxygen transfer is the most important phenomena in any bioreactor system involving production of compounds from aerobic microorganisms. Oxygen transfer efficiency can be analyzed by means of volumetric oxygen transfer coefficient (K L a). The K L a is influenced by many factors such as geometrical and operational characteristics of the vessels, rhe...