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According to the United Nations Environment Programme (UNEP), soil health is declining over the decades and it has an adverse impact on human health and food security. Hence, soil health restoration is a need of the hour. It is known that microorganisms play a vital role in remediation of soil pollutants like heavy metals, pesticides, hydrocarbons, etc. However, the indigenous microbes have a limited capacity to degrade these pollutants and it will be a slow process. Genetically modified organisms (GMOs) can catalyze the degradation process as their altered metabolic pathways lead to hypersecretions of various biomolecules that favor the bioremediation process. This review provides an overview on the application of bioengineered microorganisms for the restoration of soil health by degradation of various pollutants. It also sheds light on the challenges of using GMOs in environmental application as their introduction may affect the normal microbial community in soil. Since soil health also refers to the potential of native organisms to survive, the possible changes in the native microbial community with the introduction of GMOs are also discussed. Finally, the future prospects of using bioengineered microorganisms in environmental engineering applications to make the soil fertile and healthy have been deciphered. With the alarming rates of soil health loss, the treatment of soil and soil health restoration need to be fastened to a greater pace and the combinatorial efforts unifying GMOs, plant growth-promoting rhizobacteria, and other soil amendments will provide an effective solution to soil heath restoration ten years ahead., Graphical Abstract Schematic Representation Of Approaches Used To Restore Soil Health

Traditionally used herbs have been recognized as an important niche for fungal endophytes and the interaction between them has prompted the invention of novel metabolite. In this regard, the presen...

The problem of plastic prevalence and associated pollution has grasped the entire planet drastically, putting all fields of science on the stake seeking remedies to this global havoc. To address this crisis, with a single remediation strategy is often found to be baseless, thereby much interest has been evoked in the development of multidisciplinary approaches – involving physico-chemical and biological strategies to nullify the aftermath of plastic pollution in all possible means. Even amidst, the availability of different approaches, the use of biological methods to combat plastic degradation has gained momentum. The most frequently used plastics appear in wide forms such as polyethylene plastic bags, polypropylene-based bottles, polyvinyl chloride pipes and polystyrene styrene cups. Plastic nicknamed as one of the toughest polymers viz. polycarbonate, acrylonitrile butadiene styrene (ABS) and Polydicyclopentadiene; quite often are called so as they resist degradation in normal environmental strategies. They are often degraded in non-hostile and harsh environments of pH, temperature, radiation etc. However, not always it is possible to create such harsh environments for plastic degradation. In such a scenario, the use of gut microbes that can withstand the harsh atmosphere of gut environment could serve as promising candidates for plastic biodegradation. The current article envisages the various gut microbes of various biological agents and their role in plastic remediation. The current review compiles the techniques available for plastic remediation, the microbial prospects of plastic remediation, its challenges, and possible breakthroughs to effective plastic remediation., Graphical Abstract

Green synthesis of Nanoparticles gained much momentum because of its therapeutic uses and also has environmental benefits over traditional chemical methods. The present study describes the cost-effective eco-friendly synthesis of Zinc oxide nanoparticles from Acorus Calamus aqueous extract widely used as medicine in the traditional ayurvedic system of Kerala. The SEM analysis shows the synthesized ZnONPs are spherical and hexagonal wurtzite in structure and it was confirmed by the XRD data. The FTIR spectra revealed the role of Chemical moieties in the formation and stabilization of ZnONPs. The Acorus Calamus ZnONPs shows promising antioxidant activity and it shed light upon the role of phenolic compounds transferred from the plant during synthesis. The in vivo application of ZnONPs was very limited in the literature. The Acorus calamus ZnONPs may expect to serve as an alternative antioxidant supplement against disorders caused by oxidative stress and infections.

Plant extracts prompting free radical formation causing DNA damage among especially symbiotic microorganisms of Aedes aegypti has not been extensively examined in previous studies. Here, investigated whether: (1) it was possible to reduce the vectorial capacity by eliminating the microbial consortia of Aedes aegypti larvae, (2) the excess formation of free radical could induce damages of genomic DNA and alter the morphological appearance of Aedes aegypti larvae, and (3) which are the probable mechanisms driving the death of mosquitoes that has been treated with phytochemicals. The toxicity of Catunaregam spinosa seed extracts on the microbial community of Aedes aegypti larvae was determined as previously described. The formation of free radicals was confirmed using the ammonium molybdate method. While the GCMS method was used to assess the phytochemical analysis and the DNA lysing potential. The petroleum ether, ethanol, acetone and water extracts of Catunaregam spinosa has exhibited potent toxicity towards Aedes aegypti larvea’s gut bacterial microbiota, including Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella pneumonia, and Proteus mirabilis with strong MIC values ranging from 0.07 mg/ml to 5.9 mg/ml. Plant extract induced free radical formations and oxidative damage to DNA. The presence of the bioactive element squalene justifies the insecticidal proprieties of Catunaregam spinosa extract. This study reflects the probable mechanisms underlying the lethal effect of Catunaregam spinosa extract on Aedes aegypti, and it potential as a novel biological vector control approach.

Indiscriminate usage, disposal and recalcitrance of petroleum-based plastics have led to its accumulation leaving a negative impact on the environment. Bioplastics, particularly microbial bioplastics serve as an ecologically sustainable solution to nullify the negative impacts of plastics. Microbial production of biopolymers like Polyhydroxyalkanoates, Polyhydroxybutyrates and Polylactic acid using renewable feedstocks as well as industrial wastes have gained momentum in the recent years. The current study outlays types of bioplastics, their microbial sources and applications in various fields. Scientific evidence on bioplastics has suggested a unique range of applications such as industrial, agricultural and medical applications. Though diverse microorganisms such as Alcaligenes latus, Burkholderia sacchari, Micrococcus species, Lactobacillus pentosus, Bacillus sp., Pseudomonas sp., Klebsiella sp., Rhizobium sp., Enterobacter sp., Escherichia sp., Azototobacter sp., Protomonas sp., Cupriavidus sp., Halomonas sp., Saccharomyces sp., Kluyveromyces sp., and Ralstonia sp. are known to produce bioplastics, the industrial production of bioplastics is still challenging. Thus this paper also provides deep insights on the advancements made to maximise production of bioplastics using different approaches such as metabolic engineering, rDNA technologies and multitude of cultivation strategies. Finally, the constraints to microbial bioplastic production and the future directions of research are briefed. Hence the present review emphasizes on the importance of using bioplastics as a sustainable alternative to petroleum based plastic products to diminish environmental pollution.

Endocrine Disrupting Chemicals (EDCs), major group of recalcitrant compounds, poses a serious threat to the health and future of millions of human beings, and other flora and fauna for years to come. A close analysis of various xenobiotics undermines the fact that EDC is structurally diverse chemical compounds generated as a part of anthropogenic advancements as well as part of their degradation. Regardless of such structural diversity, EDC is common in their ultimate drastic effect of impeding the proper functioning of the endocrinal system, basic physiologic systems, resulting in deregulated growth, malformations, and cancerous outcomes in animals as well as humans. The current review outlines an overview of various EDCs, their toxic effects on the ecosystem and its inhabitants. Conventional remediation methods such as physico-chemical methods and enzymatic approaches have been put into action as some form of mitigation measures. However, the last decade has seen the hunt for newer technologies and methodologies at an accelerated pace. Genetically engineered microbial degradation, gene editing strategies, metabolic and protein engineering, and in-silico predictive approaches - modern day's additions to our armamentarium in combating the EDCs are addressed. These additions have greater acceptance socially with lesser dissonance owing to reduced toxic by-products, lower health trepidations, better degradation, and ultimately the prevention of bioaccumulation. The positive impact of such new approaches on controlling the menace of EDCs has been outlaid. This review will shed light on sources of EDCs, their impact, significance, and the different remediation and bioremediation approaches, with a special emphasis on the recent trends and perspectives in using sustainable approaches for bioremediation of EDCs. Strict regulations to prevent the release of estrogenic chemicals to the ecosystem, adoption of combinatorial methods to remove EDC and prevalent use of bioremediation techniques should be followed in all future endeavors to combat EDC pollution. Moreover, the proper development, growth and functioning of future living forms relies on their non-exposure to EDCs, thus remediation of such chemicals present even in nano-concentrations should be addressed gravely.

Wilt disease, caused by Fusarium oxysporum. f. sp. lycopersici, is a global threat to tomato production that needs to be addressed seriously. The current research envisages the use of two self-compatible Bacillus strains, Bacillus tequilensis PKDN31 and Bacillus licheniformis PKDL10, in a combinatorial approach. The spent supernatant of liquid cultures from strains PKDN31 and PKDL10 showed in vitro antifungal activity against Fusarium sp. attaining an inhibition percentage of 95.33% and 96.54%, respectively. The bacterial isolates lytic activity against Fusarium oxysporum was evaluated by scanning electron microscopic analysis and lytic enzyme production of amylase, lipase, protease and β-1,3 glucanase. Furthermore, PKDN31 and PKDL10 produced siderophores and had root colonizing ability that enhanced the biocontrol efficiency. Combined in vivo inoculation of Bacillus tequilensis PKDN31 and Bacillus licheniformis PKDL10 on tomato seeds revealed that the strains could induce systemic resistance in tomato against Fusarium oxysporum. f. sp. lycopersici by increasing defence enzymes such as β-1,3 glucanase, polyphenol oxidase, peroxidase, phenylalanine ammonia-lyase, chitinase, and total phenol accumulations. Pot culture experiments also proved the biocontrol efficacy of the above dual culture supplementation as this treatment displayed a better growth as well as defense against Fusarium challenge compared to the controls. The obtained results suggest that rhizobacterial isolates could be employed as systemic resistance inducers and biocontrol agents in tomato plants to protect against Fusarium wilt disease.

Current experimental evidence has revealed that pomegranate peel is a significant source of essential bio compounds, and many of them can be transformed into valorized products. Pomegranate peel can also be used as feedstock to produce fuels and biochemicals. We herein review this pomegranate peel conversion technology and the prospective valorized product that can be synthesized from this frequently disposed fruit waste. The review also discusses its usage as a carbon substrate to synthesize bioactive compounds like phenolics, flavonoids and its use in enzyme biosynthesis. Based on reported experimental evidence, it is apparent that pomegranate peel has a large number of applications, and therefore, the development of an integrated biorefinery concept to use pomegranate peel will aid in effectively utilizing its significant advantages. The biorefinery method displays a promising approach for efficiently using pomegranate peel; nevertheless, further studies should be needed in this area.

The augmented rates of pest infestation in stored grains have forced humans to rely on pesticide application in stored food grains even in developed countries. The greater incidence and alarming rate of pesticide resistance and safety concerns about their use in the food industry also contribute to ill-being of grain consumers and environment, thereby alluring constructive attempts to reduce the levels of agrochemical use. The current research elucidated the synergistic role of Hypericum japonicum (a medicinal plant) and pyrethroid deltamethrin in controlling the most common storage pest rice weevil, Sitophilus oryzae even at low concentrations than recommended by FAO. The screening of pesticidal property of methanolic extract of H. japonicum, pyrethroid deltamethrin, and their combinatorial assay was evaluated by standard procedures under laboratory conditions and mortality was gauged after 24 h of exposure. The LC50 and LC90 concentrations of deltamethrin alone (0.725 mg/l and 3.577 mg/l respectively) and in combination with Hypericum methanolic extract (LC50 0.119 mg/l and LC90 1.27 mg/l respectively) were found to be potent. The study revealed that the supplementation of plant extract in the pest controlling formulation substantially reduced the effective individual LC90 concentration of the pesticide required for pest control. The plant extracts showed synergy towards deltamethrin with SF 6.09. This is the foremost report on the synergistic effect of H. japonicum with deltamethrin against rice weevil, which could serve as an effective and more safer storage pest control method against the indiscriminate pesticide use and abuse.

Food and kitchen waste - omnipresent in every corner of the world serve as an excellent source of value added products owing to high organic content. Regardless of existence of various traditional methods of land filling or biogas production used to harness food waste energy, effective conversion of food to valuable resources is often challenged by its heterogenous nature and high moisture content. The current paper tries to lay down the prospects and consequences associated with food waste management. The various social, economical and environmental concerns associated with food waste management especially in terms of green house gas emission and extended rate of leachate generation also has been discussed. The difficulties in proper collection, storage and bioconversion of food waste to valuable by-products are pointed as a big hurdle in proper waste management. Finally, the wide array of value added products developed from food waste after pretreatment are also enlisted to emphasis the prospects of food waste management.

The current epidemics of vector-borne diseases in tropical countries, especially in India, have extended the need for a comprehensive understanding of the distribution of epidemiologically important vector mosquitoes. The advanced developments in genomic research including phylogenetic studies will empower the molecular studies that are vital to determine the genetic divergence and evolutionary history of mosquito vectors. The use of the cytochrome oxidase c subunit I (COI) gene-based approaches to outline the interrelationship of vector mosquitoes from different genera could also elucidate the obscurity that has risen from improper taxonomical classification. The mosquitoes were collected from Nelliyampathy, Kerala, India and identified using systematic keys and catalogues. The genomic DNA of the mosquitoes was extracted using NucleoSpin® Tissue Kit and PCR amplification of the mitochondrial COI gene was accomplished by using the following primers: Forward 5′- GGTCAACAAATCATAAAGATATTGG-3′ and reverse 5′- TAAACTTCAGGGTGACCAAAAAATCA-3′. The genetic divergence was assessed by means of the NJ-K2P method. The neighbor-joining tree was constructed using the MEGA7 software. The diversity of mosquitoes was estimated using the Shannon index through SPSS and Venn diagram plotter. The COI gene-based mitochondrial DNA analysis revealed distinct clustering of individual mosquito species within every genus together with strong bootstrap support. In total, our investigation productively identified and confirmed the interrelationship between the COI gene sequences of ten epidemiologically important mosquito species. This study also discusses the substantial evidence of mosquito species complex formation. Our findings offer a base for future research which is essential for the better understanding of mosquito phylogeny and shed light upon, a novel vector control strategy.

Nanobioremediation is a current technology which significantly contributes to the detoxification of pollutants that are harmful in the environment. Though there have been many bioremediation approaches reported over the decades, the efficiency of this technology is very high and versatile for its application in many industrial processes. Nanoparticles are of different types and, among them, metal nanoparticles are widely utilized for bioremediation of pollutants. The facile synthesis of a nanoparticle is now achieved through plants and microorganisms, leading to sustainable development. This chapter gives an overview of nanoparticles used in bioremediation applications. The chapter also briefly describes the links between remediation and biofuel generation using nanoparticles. It also identifies the research gaps and new challenges in the field of nanotechnology, especially in environment engineering applications.

Wetlands are considered as the interim zones, crammed between perpetually flooded deepwater environments and drained uplands, which support diverse range of biodiversity. Various chemical fertilizers and pesticides were used in the wetland for higher agriculture yield but the majority of them reach to non-target species especially on water birds. Studies have shown that there is a huge decrease in the population of water birds every year. Organophosphate, carbamates and organochlorines are the three major groups of pesticide widely used for agricultural purposes. Organochlorines are the potent blocker of the gamma-aminobutyric acid receptor, which is one of the major reasons for Raptor species depletion in the world. Organochlorines are banned in several countries due to its bio-accumulative nature but which still available in the markets under different brand names. The Organophosphates and carbamates have come as a replacement for organochlorines recently in wide variety of brand names.

Nanotechnology driven biocatalytic techniques have emerged as a highly efficient, practically easy, appropriate and reproducible technique for the enzyme immobilisation. Researchers were successful in developing matrix based on carbon nanotubes (CNTs) for enzyme immobilization. The enzymes immobilised on CNTs can withstand high temperature that results in enhanced and stable performance of the enzyme. This chapter focuses on CNT-based enzyme immobilisation and its implications in biofuel. Catalyst-assisted chemical vapour deposition of hydrocarbons is the most popular method of CNT synthesis due to the high quantitative yield of the process and often this process is assisted by the presence of iron and cobalt catalysts. The use of plant materials such as coconut oil as substrates to synthesise multi-walled CNTs (MWCNTs) of 80–90 nm diameter served as a green strategy of nanoparticle synthesis following the principles of vapour deposition methods. Different types of biomolecules and polymers were used to functionalise CNTs.

UNSTRUCTURED Covid 19 the causative agent of the current devastating pandemic has turned out to be a notorious virus to all men-irrespective of either common to scientific calibre. Attempts to combat this deadly virus are the need of the hour and quite often the best way to defeat an opponent is to keenly study about its structural and propagation properties. The current paper describes briefly Covid 19 at the genomic, structural and protein level to the best of our knowledge. Furthermore, the prospects of possible drug targets that could aid in the control of this virus are also discussed.

Detergents play a prominent role in various sectors of life from household to industry including a vast majority of synthetic entities. However, their indiscriminate use, unwise disposal, and concerns for environmental health have directed considerable research in the area of biosurfactants. Such biologically derived (plant or microbial) surfactants have promising properties of high biodegradability, eco-friendliness, stable surfactant properties, etc. The current chapter thus would like to systematically compare the industrial production of biosurfactants and synthetic detergents. The life-cycle analysis of various anionic and cationic detergents is verified critically to lay down the benefits as well as drawbacks of different surfactant synthetic systems along with the aftermaths they leave behind to the environment.

Heavy metals are considered as the major classes of a contaminant in nature. Heavy metal contamination from fertilizers, metal mining, and industrial activities leads to toxic effects on humans and other organisms. Although the toxic effects of these elements have been recognized for a long time, exposure to these elements continues. The toxic effects induced by them can lead to death in humans. Several advanced strategies have primarily employed to tidy up the surrounding from toxicants; however, most of the strategies are considered as problematic when getting results. The current concerns regarding the contamination due to heavy metal deposition have introduced the novel advanced technologies to detect the presence of them from soil and wastewater. Several plants have been recognized as potent herbs since they are able to absorb these toxicants. The phytoremediation techniques usually uptake the heavy metals from the soil and wastewater and recognized as a well-established approach to remediate the toxic effects induced by them. The plant-based techniques have some advantages over the conventional strategies. Therefore, the present research has focused on the various technologies used to remove the metal pollutants from natural resources especially from water and soil. These affordable and effective technologies are potentially cost-effective and environmental friendly.

Mosquito control with naturally derived herbal insecticides has gained much momentum, with the increased insecticide resistance of vectors and the multiple infectious diseases spread by them. Yet, recent studies also suggest that mosquitoes could probably transmit some cancerous cells or cancer-causing viruses from one individual to another between their blood meals. The current research thus focused on the screening and characterization of novel plants with both mosquitocidal and anticancerous properties. Accordingly, different solvent extracts of Hypericum japonicum, a key plant in Chinese medicine, were screened for its larvicidal efficacy using the fourth instar larvae of Aedes aegypti (major vector of Dengue and chikungunya). Methanolic extracts of the plant showed effective larvicidal property with LC50 7.37 ppm and LC9011.59 ppm values. The anticancerous property of the plant extract was also evaluated by in vitro cytotoxicity assay against Daltons Lymphoma Ascites (DLA) cells. The results indicated that H. japonicum plant extracts at very low concentrations of LC500.95 ppm and LC901.85 ppm were potent cytotoxic agents. To the best of our knowledge, this is the first and the foremost report of Hypericum japonicum as a potent mosquitocidal and anticancerous agent. Identification and characterization of such plant-derived bioactive plants thus could serve as a double-headed sword against the spread of infectious diseases and cancer.

Heavy metals frequently occur as silent poisons present in our daily diet, the environment we live and the products we use, leaving us victims to various associated drastic health and ecological bad effects even in meagre quantities. The prevalence of heavy metals can be traced from children's toys, electronic goods, industrial effluents, pesticide preparation, and even in drinking water in some instances; necessitating methods to remediate them. The current review discusses the various physicochemical and biological methods employed to tackle the problem of heavy metal pollution. Apart from the conventional methods following the principles of adsorption, precipitation, coagulation, and various separation techniques, the advancements made in the directions of biological heavy metal detoxification using microbes, plants, algae have been critically analyzed to identify the specific utility of different agents for specific heavy metal removal. The review paper is a nutshell of different heavy metal remediation strategies, their merits, demerits, and modifications done to alleviate process of heavy metal pollution.

The wide utility and catalytic efficiency of microbial pectinase in various industries has greatly increased its global demand. Among the natural sources of pectinases, microbial pectinases are used frequently for its ease of production and unique physicochemical properties. Yet similar to other industrial enzymes, pectinases also face the constraint of thermo-tolerance and low yield in its economised production. The current review addresses the various strategies adopted to meet the high yield and thermo-tolerance of pectinases as well as the various attempts made in the field of pectinases to its improved production and better catalytic efficiency. The utilisation of natural as well as recombinant microbial sources, metagenomic approaches, metabolic engineering, site directed mutagenesis and media engineering techniques adopted in the field of pectinases have been discussed. The significance of pectinases in various industries is depicted by enlisting its applications. To the best our knowledge the current review is unique being the first attempt to compile the recent advancements in the field of pectinases.

Since the discovery of phytic acid in 1903 and phytase in 1907, extensive research has been carried out in the field of phytases, the phytic acid degradatory enzymes. Apart from forming backbone enzyme in the multimillion dollar-based feed industry, phytases extend a multifaceted role in animal nutrition, industries, human physiology, and agriculture. The utilization of phytases in industries is not effectively achieved most often due to the loss of its activity at high temperatures. The growing demand of thermostable phytases with high residual activity could be addressed by the combinatorial use of efficient phytase sources, protein engineering techniques, heterologous expression hosts, or thermoprotective coatings. The progress in phytase research can contribute to its economized production with a simultaneous reduction of various environmental problems such as eutrophication, greenhouse gas emission, and global warming. In the current review, we address the recent advances in the field of various natural as well as recombinant thermotolerant phytases, their significance, and the factors contributing to their thermotolerance.

Bioenergy and Bioproducts have gained augmented relevance in the wake of depleting fossil fuels and escalating environmental problems induced by anthropogenic activities. The paper outlays the various applications of biomass and their significance in various processes. The prospects of lignocelluloses and algal raw materials to biofuel production are well established; however the life cycle analysis of every bioprocess becomes essential for its technical feasibility. The paper mainly targets the life cycle analysis of various pretreatment strategies adopted in the generation of biofuels. Biomass pretreatment- accounts to a major cost contributory factor in the entire production process and thus the identification of alternate cost effective strategies is of much significance. The LCA analysis identifies biofuel superior to petroleum chemicals based on its environmental effects, however better results are expected to be achieved by depending on methods using solar based energy sources for limiting fossil fuels even in processes of biofuel production.

The chapter reviews the fermentation-based production of industrially important enzymes from food waste (FW). Nearly one-third of the food produced globally is wasted and poses serious problems regarding its disposal. A number of dumping systems have been developed in the nations worldwide which has later become a threat to the environment. This problem is both of an environmental and economic concern. Recent developments in the area have revealed the application of bioremediation as the best way to dispose food waste. Composting and anaerobic digestion of the organic waste are gaining importance for the better use of household-level waste rather than just dumping it in landfill sites. This chapter focuses mainly on the different types of FW, its disposal techniques, optimization of the fermentation process for the production of different industrially valued enzymes like amylases, cellulases, pectinases, proteases, phytases, and a few others using a wide range of microorganisms from different types of food waste like kitchen waste and food processing waste.

Minerals are valuable resources gifted to man from the Mother Earth and quite often they need to be dug out from deep down with much effort to utilize them in many of our anthropogenic activities. The fascinating nature, colours as well as the physicochemical properties of minerals has extended their prospective value in the synthesis of various household and industrial products. However, knowledge of the mostly explored minerals, associated products, and their hazardous nature becomes relevant to its prevalence in our daily life. The harmful effects of some minerals are mostly evident from its site of occurrence, process of mining, post mining wastes left over and even in finished products. The current review focuses to evaluate the hazardous nature of minerals, cautions associated with its mining, drastic effects on human health, and ecosystem as an eye-opener to us. Finally, the effective remedies that could be implemented in the exploration of minerals are also discussed to the best of our knowledge. Bioleaching methods of rare earth elements and copper have been discussed briefly to explain the pros and cons of biological methods over conventional chemical leaching methods.

The growing drug resistance among microbes necessitates the identification of novel bioactive compounds from natural sources. The current study focused on isolating prospective endophytic microbes from Sida cordifolia. Different bacterial and fungal endophytes were isolated, among the isolates 3B showed substantial antibacterial and immunomodulatory activity than other isolates. The selected isolate 3B was molecularly identified as Enterobacter sp. based on 16S rDNA typing. A comparison of the biomodulatory role of the isolate Enterobacter sp. (3B) with that of the host plant extract indicated that the isolate gave comparable results with the chloroform extract of S. cordifolia plant. An evaluation on the cytotoxic properties of 3B by MTT assay indicated that it was nontoxic. To the best of our knowledge, this is the first report on the antibacterial and immunomodulatory role of Enterobacter isolate. The isolation of such promising strains with antibacterial and immunity uplifting properties would...

Chitinases – the primary chitin lytic enzyme has gained great attention due to its industrial, environmental, agriculture, medicinal and biotechnological applications. However, the industrial production of this enzyme is still at its infancy due to low yielding strains and high cost of production. The current paper targets the cumulative optimisation of chitinase production from low cost substrate chitin using high yielding novel chitinase producing strain. Bacterial chitinase producers were isolated from the potential mangrove ecosystem of Valanthakad, Cochin, Kerala. Among the various isolates, the best chitinase producer MCB-7 identified as Bacillus pumilus exhibited an inherent high chitinase activity of 3.36 U/mL. Using Plackett–Burman design the factors such as chitin concentration, peptone and pH were found to be significant. Further optimisation with a multivariate statistical approach using Box–Behnken design resulted in a 6.9 fold increase of chitinase activity to a final yield of 23.19 U/mL. The use of cheap and consistent nature of the chitin as carbon source along with a high chitinase yielding isolate would be beneficial in providing consistent yields of the enzyme. To the best of our knowledge, this is the first report on high chitinase yielding B. pumilus strains from mangroves. The current isolate of B. pumilus MCB-7 is also unique in its halotolerance, pH tolerance and thermostability – which could widen its spectrum of applications.

The relevance of enzyme fortification in animal feeds has been well established and exploited to generate a high income generating sector of industrial enzymes. Apart from aiding the better nutritional uptake and utility of the food constituents from the animal feed, the economic benefits gained by the production of better meat yield from livestock has prompted the acceptability of these enzymes in the feedstock. The current review outlines the various types of enzymes supplemented in animal feeds, their functional role and advantages of feed enzymes on animal growth and productivity. The effectiveness of feed enzymes in reducing the release of unused residual metabolites into the environment and the contributory role of these enzymes in diminishing the aftermaths of global warming are also discussed. The various strategies adopted in the individual and combinatorial generation of feed enzymes, their substrates and the characteristics of such feed enzymes are also presented in a concise manner. Finally, the advancements in the industrial production of feed enzymes and its supplementation are reviewed.

The non-conventional yeasts Kluyveromyces lactis, Yarrowia lipolytica, Ogataea polymorpha and Pichia pastoris have been developed as eukaryotic expression hosts because of their desirable growth characteristics, including inhibitor and thermo-tolerance, utilisation of diverse carbon substrates and high amount of extracellular protein secretion. These yeasts already have established in the heterologous production of vaccines, therapeutic proteins, food additives and bio-renewable chemicals, but recent advances in the genetic tool box have the potential to greatly expand and diversify their impact on biotechnology. The diversity of these yeasts includes many strains possessing highly useful, and in some cases even uncommon, metabolic capabilities potentially helpful for the bioprocess industry. This review outlines the recent updates of non-conventional yeast in sustainable bioprocesses.

Microbial remediation is commonly used to treat environmental samples polluted by anionic surfactants. However, this method is often limited due to the pathogenicity of the microbes used to clean environmental samples. Therefore, we aimed to isolate nonpathogenic bacterial strains capable of degrading sodium dodecyl sulfate. We used conventional enrichment culture. Strains were screened by methylene blue active substance assay and HPLC. The primary sodium dodecyl sulfate splitting enzyme alkylsulfatase was isolated by column chromatography. The enzymatic conversion of sodium dodecyl sulfate to dodecanol was followed by zymogram analysis. The biosurfactant producing ability of the isolate was measured using Siegmund Wagner blue agar, and the emulsification index was measured. The isolate was identified as Pseudomonas plecoglossicida S5 (JN700182), based on biochemical analysis and 16S rRNA sequencing. This strain S5 was able to degrade 89.28 ± 0.56 % of sodium dodecyl sulfate at 10 g/L. This strain produced a single type of alkylsulfatase enzyme and rhamnolipid biosurfactant in response to sodium dodecyl sulfate. Moreover, a 20 day fish study proved the nonpathogenicity of S5. This is the first report of sodium dodecyl sulfate degradation by P. plecoglossicida.

The growing industrial development and concomitant efforts to protect mother Earth from alleviating pollution levels has greatly demanded the use and disposal of milder chemicals and xenobiotics. Of the widely used xenobiotics, surfactants have an increasing market demand due to its prevalent role in pharmaceutical preparations, food industry as well as almost all foaming products. The use of biosurfactants in place of chemical surfactants has gained momentum owing to the low toxicity, higher biodegradability and better environmental compatibility of biosurfactants. The current review outlays the various biosurfactants produced and their significance in various industries. An outline of the various biosynthetic pathways, challenges and advancements in the synthesis of the two mostly used biologically synthesised biosurfactants—rhamnolipids and sophorolipids has been discussed.

Anionic surfactants like sodium dodecyl sulphate (SDS), due to its extensive disposal to water bodies cause detrimental effects to the ecosystem. Among the various attempts to reduce the after effects of these toxicants, microbial induced bioremediation serves as a promising strategy. The current study aimed to develop a three stage bioreactor to remediate anionic surfactants in wastewater using effective bacterial isolates. Screening of effective SDS biodegraders led to isolation of Pseudomonas aeruginosa (MTCC 10311). Treatment of synthetic effluent with an immobilized packed bed reactor at a flow rate of 5 mL h−1 resulted in 81 ± 2% SDS eliminations and 70 ± 1% reduction in chemical oxygen demand (COD) in five cycles (6 h per cycle). The hydraulic retention time of the reactor was found to be 6 h. Combinatorial usage of a three stage bioreactor, involving aeration, adsorption with low cost scrap rubber granules and treatment with immobilized Pseudomonas aeruginosa, successfully reduced SDS concentrations and COD of wastewater to 99.8 ± 0.1% and 99 ± 1%, respectively, in 18 h by continuous treatment. Half-life of the three stage bioreactor was 72 h. In addition to reducing the surfactant concentrations, this novel bioreactor could resolve the surfactant associated foaming problems in treatment plants, which make it more unique.

Previous studies indicate that high concentration of pesticides and their associated toxic effects are high at their point source of application. Use of pesticide-degrading bacteria at point sources could augment degradation and thereby reduce toxic effects associated with pesticide persistence in soil. Quinalphos, an organophosphorus insecticide, though ranked “moderately hazardous” in the WHO's acute hazard ranking, still continues to be used extensively in developing countries. The presence of a chloride radical usually makes this pesticide sparingly soluble in water and hence difficult to degrade. The present study aimed to isolate autochthonous bacterial strains capable of utilizing quinalphos as a carbon source. Primary screening of pesticide-contaminated soil by enrichment culture and degradation analysis by UV-VIS spectrophotometry led to the isolation of 12 different bacterial isolates, of which three efficient isolates of Pseudomonas sp, Serratia sp, and Pseudomonas aeruginosa with degradation r...

Surfactants toxicity has induced a worldwide alert followed by various regulations. There are still concerns about the biodegradability and ecofriendliness of surfactants. Reviews on surfactants are available, but a concise manuscript covering surfactant types, primary and secondary toxicity of surfactants, evaluating the level of surfactant pollution worldwide, is needed. We review here the safety of surfactants in the aquatic system, in terrestrial ecosystems and for humans. We discuss strategies to solve surfactant contamination. Remediation methods include ozonation, UV radiation and catalyst-coupled auto-oxidation. We focus on the biodegradation of the anionic detergents sodium dodecyl sulfate and linear alkyl benzene sulfonate. Finally, the relevance and role of biosurfactants as alternatives to synthetic detergents are also described.

The multifaceted role of chitinase in medicine, agriculture, environmental remediation and various other industries greatly demands the isolation of high yielding chitinase producing microorganisms with improved properties. The current study aimed to investigate the isolation, characterization and biocontrol prospective of chitinase producing bacterial strains autochthonous to the extreme conditions of mangrove ecosystems. Among the 51 bacterial isolates screened, Bacillus pumilus MCB-7 with highest chitinase production potential was identified and confirmed by 16S rDNA typing. Chitinase enzyme of MCB-7 was purified; the chitin degradation was evaluated by SEM and LC-MS. Unlike previously reported B.pumilus isolates, MCB-7 exhibited highest chitinase activity of 3.36 U/mL, active even at high salt concentrations and temperature up to 60 °C. The crude as well as purified enzyme showed significant antimycotic activity against agricultural pathogens such as Aspergillus flavus, Aspergillus niger, Aspergillus fumigatus, Ceratorhiza hydrophila and Fusarium oxysporum. The enzyme also exhibited biopesticidal role against larvae of Scirpophaga incertulas (Walker). [Lep.: Pyralidae], a serious agricultural pest of rice. The high chitinolytic and antimycotic potential of MCB-7 increases the prospects of the isolate as an excellent biocontrol agent. To the best of our knowledge, this is the first report of high chitinase yielding Bacillus pumilus strain from mangrove ecosystem with a biocontrol role against phytopathogenic fungi and insect larval pests.

Sodium dodecyl sulphate (SDS), an anionic surfactant, has been used extensively due to its low cost and excellent foaming properties. Fifteen different bacterial isolates capable of degrading SDS were isolated from detergent contaminated soil by enrichment culture technique and the degradation efficiency was assessed by Methylene Blue Active Substances (MBAS) assay. The most efficient SDS degrading isolate was selected and identified as Pseudomonas aeruginosa S7. The selected isolate was found to harbor a single 6-kb plasmid. Acridine orange, ethidium bromide, SDS and elevated temperatures of incubation failed to cure the plasmid. The cured derivatives of SDS degrading Pseudomonas aeruginosa were obtained only when ethidium bromide and elevated temperature (40 °C) were used together. Transformation of E. coli DH5α with plasmid isolated from S7 resulted in subsequent growth of the transformants on minimal salt media with SDS (0.1%) as the sole source of carbon. The SDS degradation ability of S7 and the transformant was found to be similar as assessed by Methylene Blue Active Substance Assay. The antibiotic resistance profiles of S7, competent DH5α and transformant were analyzed and it was noted that the transfer of antibiotic resistance correlated with the transfer of plasmid as well as SDS degrading property.

AIMS Biological synthesis of rhamnolipids from SDS by Pseudomonas aeruginosa S15 is found to be a cost effective mode of rhamnolipid synthesis. This study aimed to attempt rhamnolipid synthesis by transformant Escherichia coli DH5α cells. METHODS AND RESULTS Molecular analysis by curing experiments revealed that the properties of SDS based rhamnolipid synthesis were plasmid borne. Transformation of 10 kb plasmid to E. coli DH5α cells conferred rhamnolipid synthetic ability to transformant. Various genetic elements involved in SDS based rhamnolipid synthesis were analyzed using PCR based and restriction digestion based approaches. PCR amplification using primers specific for sdsA gene encoding alkylsulfatases yielded two significant amplicons viz, 1·2 kb fragment and 422 bp fragment, coding for putative dehydratase and ABC transporter respectively. Amplicon of sdsB gene lacked ability of SDS degradation and rhamnolipid synthesis. Rhamnolipid biosynthesis by transformant E. coli DH5α containing the whole of the 10 kb plasmid, was optimized to yield of 3·38 g l(-1) in 5 days of incubation. CONCLUSIONS Plasmid encoded rhamnolipid synthesis from recombinant E. coli cells is novel and could serve as yet another promising approach among various steps adopted for safe and effective rhamnolipid synthesis. SIGNIFICANCE AND IMPACT OF THE STUDY SDS based rhamnolipid synthesis by S15 attained a high substrate (SDS) to product (Rhamnolipid) conversion ratio. However, the use of Pseudomonas strains is always discouraged as they are opportunistic pathogens and could sometimes turn infectious. Thus, transformation of genetic elements coding SDS based rhamnolipid synthesis to nonpathogenic strains could be promising.

Surfactant toxicity has aroused a worldwide alert leading to various regulations on its usage and disposal. In this context much concern arises regarding the biodegradability and eco-friendliness of surfactants. Various reviews on surfactant and its toxicity are available; however there is a lack of a concise review covering surfactant types, primary and secondary toxicity of surfactants, evaluating the level of surfactant pollution worldwide. This chapter describes the safety concerns of surfactants on the aquatic system, terrestrial ecosystem and particularly on humans. We present remediation methods to solve surfactant contamination, such as ozonation, UV radiation, catalyst coupled autooxidation. Biological degradation of surfactants is highlighted with reference to the most commonly used anionic detergents sodium dodecyl sulfate (SDS) and linear alkyl benzene sulfonate (LAS). Biodegradation pathways and mechanism are discussed. Green surfactants are presented. Finally the relevance and role of biosurfactants as alternatives to synthetic detergents is described.

The utility of rhamnolipids in industry is currently limited due to the high constraints in its economic production. In this scenario, the novel utility of sodium dodecyl sulphate (SDS) as carbon source could serve as promising cost-effective strategy. Screening of effective SDS biodegraders led to the isolation of Pseudomonas aeruginosa S15 capable of concomitant SDS degradation and biosurfactant synthesis. SDS-based rhamnolipid production was proved on SDS minimal agar plates using cetyl trimethylammonium bromide-methylene blue method and optimised in SDS-based minimal salt (SBS) medium. SDS proved to be an ideal carbon source for rhamnolipid synthesis with a high substrate to product conversion rate yielding 6.9 g/l of rhamnolipids from 1 g/l SDS in 5 days. Fast atom bombardment mass spectroscopy analysis of the purified biosurfactant proved the presence of mono- and di-rhamnolipids, viz., Rha-C(10)-C(10), Rha-C(10)-C(12) and Rha-Rha-C(10)-C(10) with surface active properties. The secreted rhamnolipids were not utilised by S15 as a carbon source, but it caused a dispersion of bacterial biofilms in SBS medium. To the best of our knowledge, this is the first report on bioconversion of synthetic detergent to biodetergent. This SDS-based novel methodology presents a more economised mode of rhamnolipid synthesis utilising SDS as sole carbon source.