Biofilm in aquaculture production
Abstract
A biofilm is an assemblage of microbial cells which is irreversibly associated with a surface and enclosed in a matrix of primarily polysaccharide material. It may form on a wide variety of surfaces, including living tissues, medical devices, industrial or potable water system pipe or natural aquatic systems. A well-diversified organism such as algae, bacteria, protozoa, arthropods, etc. may be observed in the biofilm assemblage. The biofilm structure depends on the nature of substratum, hydrodynamics of system, nutrient availability, light and grazing capacity of organism. It has been observed that the introduction of substrata for the development of biofilm in the aquaculture system play a significant role. Biofilm organisms are microscopic and highly nutritious. The organisms of biofilm may serve as single cell protein and are easily harvested by all size of cultured species in aquaculture as compared to planktonic organism in the water column. Biofilms are considered as good quality protein source (23-30%). Microalgae and heterotrophic bacteria are rich source of immune enhancers, growth promoters, bioactive compounds and dietary stimulants which can enhance growth performance of cultured organism. Substrata minimize the mortality by providing shelter and hiding places to cultured organisms. The attached nitrifying bacteria contained in biofilm improve the water quality by lowering ammonia waste from culture system through nitrification process. Biofilm based low cost technology will help resource poor farmers in generating protein rich nutrient in sustainable manner from aquaculture. An attempt has been made to review the role of biofilm in aquaculture.
... Among them, nitrifying bacteria are key to maintaining water quality by detoxifying the ammonia produced by the fish. In addition, biofilms growing on submerged substrata can improve shrimp production, and they are considered a good quality protein source (Pandey et al. 2014). However, biofilms could also provide the appropriate environment for fish pathogens to persist in systems and withstand disinfection protocols or even antibiotic treatments (Miller et al. 2015;Almatroudi et al. 2016). ...
... CAI AND ARIAS in intensive systems by providing additional food sources (Pandey et al. 2014). However, biofilms can also harbor pathogens in fish farms and natural ecosystems (King et al. 2004;Hall-Soodley and Stoodley 2005;Pandey et al. 2014). ...
... CAI AND ARIAS in intensive systems by providing additional food sources (Pandey et al. 2014). However, biofilms can also harbor pathogens in fish farms and natural ecosystems (King et al. 2004;Hall-Soodley and Stoodley 2005;Pandey et al. 2014). Recently, F. columnare was isolated from biofilms present in Finnish lakes connected to fish farms suggesting biofilm could serve as reservoir for this pathogen in the environment (Kunttu et al. 2012). ...
... The free-living bacteria would benefit from the suspended particles of organic matter while the cells attached forming part of the biofilm would be better protected against external factors (Balcázar, Subirats, and Borrego 2015). The raising interest to study the mechanisms behind biofilm formation and the role of such structures in aquaculture is due to its implications in water quality (Pandey, Bharti, and Kumar 2014). Some microorganisms colonising the surfaces and sediment of the tanks are able to aerobically and/or anaerobically remove the products that typically accumulate at the aquaculture system, which are mainly ammonium, nitrite, nitrate, phosphate and organic matter (Thompson, Abreu, and Wasielesky 2002). ...
The microbial communities in aquaculture systems are primarily affected by changes in water quality, fish metabolism, feeding strategies and fish disease prevention treatments. Monitoring changes in aquatic microbiomes related to aquaculture activities is necessary to improve management strategies and reduce the environmental impact of aquaculture water discharge. This study assessed the effects of activities within two fish farms on water microbiome composition by analysing the water entering and leaving both systems. Additionally, pathogenic bacterial species associated with common fish diseases were identified. The abundance, diversity and identity of microorganisms were evaluated using 16S rRNA hypervariable gene region amplicon sequencing. Proteobacteria (38.2%) and Bacteroidetes (31.3%) were the most abundant phyla in all water samples. Changes in microbiome composition after passage through the fish tanks were observed in several taxa, such as Nitrospirae, Chloroflexi, Deferribacteres and Cyanobacteria. Flavobacterium sp. and Pseudomonas sp. were the predominant potential pathogens and heterotrophic bacteria detected in both farms. Several chemolithotrophic bacteria and archaea were found in the natural reservoir used for aquaculture activities, while water microbiomes in the aquaculture systems were generally dominated by heterotrophic organisms.
... Biofilms on submerged surfaces result from the selective attachment of microorganisms, facilitation, and interspecific competition in the microbial communities (Rummel et al., 2017). Biofilm systems offer an environmentally friendly approach to aquaculture by utilizing natural food sources and reducing reliance on commercial feeds (Pandey et al., 2014;Yadav et al., 2021). ...
Aim: Biofilm-based aquaculture systems, proven cost-effective, reduce the need for expensive supplementary feed. The biofilm acts as a natural planktonic food source for reared organisms. Previous research highlighted the influence of fish stocking density and biomass on plankton diversity in different aquaculture settings, underscoring the significance of these factors in biofilm-based systems. Hence, the present study attempted to understand how varying stocking densities of pearlspot (Etroplus suratensis) influence plankton diversity indices in the biofilm-based aquaculture system.
Methodology: The present experiment was designed in 5 Practical Salinity
Unit (PSU) brackish water with soil-bottomed FRP circular (500 L) tanks for
60 days. The sugarcane bagasse was used as a substrate for biofilm
production after fertilization with cow dung, urea, and lime. Fries of pearlspot
(4.67 ± 0.04 mm/1.71 ± 0.03 g) were stocked at four different stocking
densities in triplicates viz T 1 (50 nos); T 2 (100 nos), T 3 (150 nos) and T 4 (200
nos) fish fry m -3 in the biofilm-based rearing system. Plankton samples were
collected from water and biofilm deposited on the substrate and analyzed for
diversity indices. The Shannon Diversity Index, Simpson Diversity Index,
Simpson Dominance Index, and Margalef Richness Index were used to compute the plankton diversity indices in different treatments using standard equations.
Results: In the current investigation, lower stocking densities with lower fish biomass were associated with significantly higher (P≤0.05)
Shannon Diversity Index, Simpson Diversity Index, and Margalef Richness Index in water. In contrast, the Simpson Dominance Index in water
showed a significantly lower (P≤0.05) value for treatments with lower fish biomass than for treatments with higher biomass.
Interpretation: The values obtained for various diversity indices indicated that a biofilm-rearing system with lower E. suratensis biomass
produced more planktonic abundance, evenness, and species richness.
... The mechanism has been mentioned in our former study [26]. The ES can offer shelter and cover [52], broaden the surface area for microorganisms to attach to [16], decrease water ammonia nitrogen, and inhibit opportunistic pathogens in the water and the fish gut [24]. All these reasons bring the higher survival rate and output of the fish, and the higher feed utilization efficiency in the treatment system than the control ecosystem. ...
Aquaculture supplies high-quality and healthy proteins. With the increasing human demand for aquaculture production, intensive pond aquaculture developed rapidly and results in environmental deterioration. To solve this problem, the eco-substrate (ES), which is the biofilm carrier, has been utilized in aquaculture ponds. Studying the ecological mechanisms of ES from the perspective of the ecosystem may be conducive to the sustainable development of aquaculture. In this study, it was evaluated how ES makes a difference to the trophic structure, energy flow, and system characteristics of two different aquaculture pond ecosystems via the ecopath model. Three aquaculture ponds with ES were designed as the treatment ecosystem and three aquaculture ponds without ES were designed as the control ecosystem. There were 13 and 14 functional groups in the control and treatment ecosystems, respectively. The results showed that (1) the macrozooplankton and microzooplankton showed strong effects on the ecosystem in the keystoneness index; (2) energy transfer pathways in the treatment system with ES increased by 26.23% compared to the control system; (3) the ES improved the utilization rate of detritus, which was 14.91% higher than that of the control ecosystem; (4) the material and energy flow index and network information characteristics demonstrated the ES enhanced the complexity and stability of the treatment system. To improve the energy utilization efficiency, filter feeders can be introduced to ES ponds. Overall, the ES can alter the trophic structure, improve the energy utilization efficiency, and enhance the stability and maturity of aquaculture ecosystems, representing a sustainable practice. Considering the total area of aquaculture ponds on the earth reaching more than 5 million hectares, the application prospect of ES is broad.
... Because bacteria may form biofilms and persist in water even when they are not associated with the host, aquaculture has become particularly vulnerable to bacterial diseases [25]. Therefore, identifying novel LAB isolates and EPS effective against these fish pathogens and biofilm producers is thus viewed as a line of defense against these detrimental effects on the marine environment. ...
Background
In recent years, the demand for innovative antimicrobial agents has grown, considering the growing problem of antibiotic resistance in aquaculture. Adult Apis mellifera honeybees’ gut represents an outstanding habitat to isolate novel lactic acid bacteria (LAB) able to produce prominent antimicrobial agents.
Methods
In the current study, twelve LAB were isolated and purified from the gut of adult Apis mellifera. The isolates were screened for exopolysaccharide (EPS) production. The most promising isolate BE11 was identified biochemically and molecularly using 16 S rRNA gene sequence analysis as Enterococcus sp. BE11 was used for the mass production of EPS. The partially purified BE11-EPS features were disclosed by its physicochemical characterization. Moreover, the antimicrobial activity of BE11 cell free supernatant (CFS) and its EPS was investigated against some fish pathogens namely, Pseudomonas fluorescens, Streptococcus agalactiae, Aeromonas hydrophila, Vibrio sp. and Staphylococcus epidermidis using well-cut diffusion method.
Results
The physicochemical characterization of BE11-EPS revealed that the total carbohydrate content was estimated to be ~ 87%. FTIR and NMR analysis ascertained the presence of galactose and glucose residues in the EPS backbone. Moreover, the GC-MS analysis verified the heterogeneous nature of the produced BE11-EPS made up of different monosaccharide moieties: galactose, rhamnose, glucose, arabinose sugar derivatives, and glucuronic acid. BE11 CFS and its EPS showed promising antimicrobial activity against tested pathogens as the inhibition zone diameters (cm) ranged from 1.3 to 1.7 and 1.2–1.8, respectively.
Conclusion
The bee gut-resident Enterococcus sp. BE11, CFS, and EPS were found to be promising antimicrobial agents against fish pathogens and biofilm producers affecting aquaculture. To the best of our knowledge, this is the first study to purify and make a chemical profile of an EPS produced by a member of the bee gut microbiota as a potential inhibitor for fish pathogens.
... For instance, considering, among other traits, the ability of microalgae to form biofilms, should be useful in the selection of strain(s) to be used in wastewater treatment and/or toxicity measurements as biosensors [21,59]. Additional potential applications of microalgal biofilms include their use in the control of fish bacterial pathogens in aquaculture systems [60,61], as well as in quality improvement and shelf-life extension of seafood products [62,63]. ...
The food system and the surrounding environment support the growth of an extensive spectrum of microorganisms. Most bacteria are capable of adhering and forming biofilms, where they can endure and thrive for several days, weeks, or even longer, contingent upon the type of bacterium and the surrounding circumstances. Biofilms undergo several phases of development in their biological cycle, including preliminary attachment, maturity, maintenance, and dispersal. To be more precise, biofilms serve as a continuous breeding ground for bacteria including Salmonella enterica, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Listeria spp. These bacteria can cause serious infections such as nosocomial infections and foodborne illnesses, as well as contaminate food pipelines. Consequently, biofilm-forming pathogenic microbes in the dairy, meat, poultry, and aquaculture food sectors are substantial issues due to these types of biofilms. Accordingly, the food industry places a high priority on preventing the formation of biofilms and eliminating those that have already developed. The production of biofilms has been reported to be inhibited by natural resources such as biopeptides, essential oils, plant extracts, and enzymes such as glycosidases, proteases, and DNases. Cold plasma treatment, pulsed electric field, power ultrasound, and pulsed light technology are some of the cutting-edge methods that have been used recently to identify and assess microorganisms adhered to surfaces. An improved understanding of the physiology, architecture, and molecular signalling of biofilms can help prevent and manage food-related spoilage and harmful microorganisms. Therefore, the study addresses the development of biofilm in the food environment, possible health risks related to it, environmental variables that play a role, and possible approaches for controlling it.
The use of algae as a natural and sustainable method for treating wastewater has attracted considerable attention in recent years because of its potential to minimize the environmental impact of conventional wastewater treatment procedures. The chapter overviews the most cutting-edge algal-based wastewater treatment technologies currently available, including open pond systems, photobioreactors, and hybrid systems. This can potentially provide sustainable solutions for water pollution control while creating new revenue streams. Additionally, it covers the benefit and drawbacks of each technology as well as its economic viability. The chapter emphasizes the significance of considering socioeconomic factors when putting algal-based wastewater treatment systems into place. These elements include stakeholder participation, public perception, and community acceptance. Furthermore, this chapter covers the possibility of using algae-based wastewater treatment to provide new revenue opportunities by producing added-value biofuels, bioplastics, and other products. In addition, we carried out a bibliometric analysis with a particular emphasis on applying algal technologies in wastewater treatment. It seeks to pinpoint gaps, trends, and patterns in the literature on this issue. An additional study is necessary for the optimal use of these technologies and to guarantee their long-term survival in various socio-economic factors.
This book contains 18 chapters and provides an international review of periphyton ecology, exploitation and management. The ecological aspect focuses on periphyton structure and function in natural systems while the exploitation aspect covers its nutritive qualities and utilization by organisms, particularly in agriculture. The management aspect considers the use of periphyton for increasing aquatic production and its effects on water quality and animal health in culture systems. Topics covered include: periphyton and aquatic production; periphyton structure, diversity and colonization; periphyton dynamics and influencing factors; periphyton in the aquatic ecosystem and food webs; periphyton in freshwater lakes and wetlands; utilization of periphyton for fish production in ponds; adaptation to feeding in herbivorous fish; traditional brush park fisheries in natural waters; periphyton as biological indicators in managed aquatic ecosystems; effect of periphyton on water quality; similarities between microbial and periphytic biofilms in aquaculture systems; periphyton-based pond polyculture; research of periphyton-based aquaculture in India; periphyton-based cage aquaculture; utility of added substrates in shrimp culture; importance of periphyton in abalone culture; periphyton-based aquaculture in Asia; and knowledge gaps and directions for future research in the main aspects discussed in the book.
The influence of dissolved oxygen concentration in nitrification kinetics was studied in a new biofilm reactor, the circulating bed reactor (CBR). The study was carried out partly at laboratory scale with synthetic water containing inorganic carbon and nitrogen compounds, and partly at pilot scale for secondary and tertiary nitrification of municipal wastewater.
The experimental results showed that either the ammonia or the oxygen concentration could be limiting for the nitrification rate. The transition from ammonia to oxygen limiting conditions occurred for an oxygen to ammonia concentration ratio of about 1.5 - 2 gO2/gN-NH4+ for both laboratory- and pilot-scale reactors. The nitrification kinetics of the laboratory-scale reactor was close to a half order function of the oxygen concentration, when oxygen was the rate limiting substrate.
