Divya Prakash

Actinomycetes: A Repertory of Green Catalysts with a Potential Revenue Resource

Biocatalysis, one of the oldest technologies, is becoming a favorable alternative to chemical processes and a vital part of green technology. It is an important revenue generating industry due to a global market projected at

Biocatalytic potential of an alkalophilic and thermophilic dextranase as a remedial measure for dextran removal during sugar manufacture

7 billion in 2013 with a growth of 6.7% for enzymes alone. Some microbes are important sources of enzymes and are preferred over sources of plant and animal origin. As a result, more than 50% of the industrial enzymes are obtained from bacteria. The constant search for novel enzymes with robust characteristics has led to improvisations in the industrial processes, which is the key for profit growth. Actinomycetes constitute a significant component of the microbial population in most soils and can produce extracellular enzymes which can decompose various materials. Their enzymes are more attractive than enzymes from other sources because of their high stability and unusual substrate specificity. Actinomycetes found in extreme habitats produce novel enzymes with huge commercial potential. This review attempts to highlight the global importance of enzymes and extends to signify actinomycetes as promising harbingers of green technology.

Actinomycetes: Role in Biotechnology and Medicine

The present study is focused on dextranase from Streptomyces sp. NK458 with potential to remove dextran formed during sugar manufacture. The dextranase had molecular weight of 130 kDa and hydrolyzed 15-25 and 410 kDa dextran. Dextranase production was optimized using statistical designs and the enzyme was purified 1.8-fold with 55.5% recovery. It displayed maximum activity at pH 9.0 and 60°C and was stable over a wide range of pH from 5.0 to 10.0. The k(m) and V(max) values were 3.05 mM and 17.97 mmol/ml/h, respectively. Ten units of dextranase could reduce dextran content by 67% in 24h and 56% in 72 h from sugarcane juice of cane variety CoS 86032. The enzyme was stable up to 3 days at 30°C beyond which its activity decreased and dextran removal could be retained by supplementation of 5 U of dextranase. These properties make it a promising biocatalyst for sugar industry.

Microbial Mining of Value Added Products from Seafood Waste and Their Applications

Actinomycetes, one of the most diverse groups of filamentous bacteria, are well recognized for their metabolic versatility. The bioactive potential of these bacteria facilitates their survival even in distress and unfavourable ecological conditions. This special issue is dedicated to the importance of multitude of primary and secondary metabolites produced by actinomycetes. The six articles published in this issue balance the biocatalytic and biocidal potential of actinomycetes. The importance of large repertory of enzymes from actinomycetes and their potential in replacing chemical catalysts is discussed. Successful commercialization of these enzymes is an important step towards revolutionizing “green technology.” Reduction in the cost of enzyme production is demonstrated by production of endoglucanases from Streptomyces sp. on low-cost substrates. Such low-cost production initiatives can be extended to other enzymes and metabolites. Novel properties like thermal and ionic stabilities and a better turnover make these systems infallible and regenerative. The activity of enzymes from actinomycetes is not confined to substrate conversion alone but broadened to biocontrol of quorum-sensing-dependent phytopathogens, as mediated by acyl-homoserine-lactone-degrading enzymes from endophytic actinomycetes. Unexplored environments often appeal to researchers in the hope of accruing novel bacteria, a continuous quest which has actually led to discovery of unusually industrious microbes. Antimicrobial potential of actinobacteria isolated from the integument of Trachymyrmex fungus-growing ants is on par with commercial antimicrobials, clearly manifesting a new explorable niche “actinobacterial symbionts of plants and animals.” The term “antimicrobials” often leads our thoughts to “medicine-related” but its “environment-related” applications are less contrived. Streptomyces lunalinharesii produces antimicrobial substances against sulfate-reducing bacteria commonly responsible for corrosion in the petroleum industry, with an ability to replace the existing biocides. Making the best out of the already good can be achieved for actinomycetes by strain improvement. Advanced microarray-driven reverse engineering strategies for the understanding and modulation of independently functioning regulatory pathways can allow these microfactories to overproduce important antibiotics. In a nutshell, actinomycetes offer the most promising synthesizers of many industrially and commercially meaningful metabolites. Novel and unexplored habitats may offer bacterial assemblages not reached hitherto. An integration of newer habitats, screening, and improvement technologies can offer promising candidates for biotechnology and health-related applications. Neelu Nawani Bertrand Aigle Abul Mandal Manish Bodas Sofiane Ghorbel Divya Prakash

Diverse pathological implications of YKL-40: Answers may lie in ‘outside-in’ signaling

Waste management is the current focus of the decade towards a greener and cleaner environment. Waste management involves effective, safer and efficient methods that can degrade waste and reduce the release of pollutants. The seafood industry generates around 312 tons waste annually that poses a serious crisis for degradation and waste management. The marine waste contains valuable products like chitin, chitosan, their oligosaccharides, proteins, pigments, etc. which can be extracted and used for commercial applications. The chemical methods employed for their production have numerous disadvantages like low recovery, high cost and the release of hazardous effluents, thus biological conversion which is cost effective, efficient and environment friendly, is the best alternative to recover these value added products. This review describes the value added products that are biologically extracted from marine waste and their applications in the field of biotechnology.