Diversity of Pigments in Insects,Their Synthesis and Economic Value for Various Industries

Pigments play an essential role in imparting colors to the various organs of invertebrates particularly,insects.Genetic evolution and adaptive pigmen­tation of invertebrates have been studied which depicted that insect colors respond to the climatic changes.The physical,chemical and structural properties of insect pigments are being studied by researchers for years to elucidate their evolutionary aspects of physiology,metabolism,and eco­nomic importance for human welfare.Color development in insects varies within the species of different genera.In this state-of-the-art literature review,we discuss the variety of pigments other than visual ones found in different species of insects.The review also highlights the potential benefits or functions of pigments to insects.

Exploring the region-wise diversity and functions of symbiotic bacteria in the gut system of wood-feeding termite,Coptotermes formosanus,toward the degradation of cellulose,hemicellulose,and organic dyes

The wood-feeding termite Coptotermes formosanus represents a unique and impressive system for lignocellulose degradation.The highly efficient digestion of lignocellulose is achieved through symbiosis with gut symbionts like bacteria.Despite extensive research during the last three decades,diversity of bacterial symbionts residing in individual gut regions of the termite and their associated functions is still lacking.To this end,cellulose,xylan,and dye-decolorization bacteria residing in foregut,midgut,and hindgut regions of C.formosanus were enlisted by using enrichment and culture-dependent molecular methods.A total of 87 bacterial strains were successfully isolated from different gut regions of C.formosanus which belonged to 27 different species of 10 genera,majorly affiliated with Proteobacteria(80%)and Firmicutes(18.3%).Among the gut regions,37.9%of the total bacterial isolates were observed in the hindgut that demonstrated predominance of cellulolytic bacteria(47.6%).The majority of the xylanolytic and dye-decolorization bacteria(50%)were obtained from the foregut and midgut,respectively.Actinobacteria represented by Dietza sp.was observed in the hindgut only.Based on species richness,the highest diversity was observed in midgut and hindgut regions each of which harbored seven unique bacterial species.The members of Enterobacter,Klebsiella,and Pseudomonas were common among the gut regions.The lignocellulolytic activities of the selected potential bacteria signpost their assistance to the host for lignocellulose digestion.The overall results indicate that C.formosanus harbors diverse communities of lignocellulolytic bacteria in different regions of the gut system.These observations will significantly advance our understanding of the termite–bacteria symbiosis and their microbial ecology uniquely existed in different gut regions of C.formosanus,which may further shed a light on its potential values at termite-modeled biotechnology.

Statistical optimization of lignocellulosic waste containing culture medium for enhanced production of cellulase by Bacillus tequilensis G9

The ever increasing energy demands of modern civilization and rapidly dwindling fossil fuels point towards a renewable substitute like biofuels.However,higher costs associated with biofuel productions is the major bottleneck for its commer-cialization.The present study demonstrates the use of a statistical approach called response surface methodology(RSM)to investigate the optimum parameters for maximum production of cellulase by Bacillus tequilensis G9.The Plackett-Bur-man design(PB)of the RSM analysis indicated grass straw(GS)concentration,pH,FeSO4,inoculum,MgSO4,incubation period and NH4Cl as significant variables that influence the cellulase production.Further,to propose the best medium for the maximum production of cellulase by B.tequilensis G9,the most influential parameters,namely concentrations of GS as substrate,FeSO4,pH,inoculum size,etc.were fine-tuned by central composite design(CCD)involving four factors and five levels.The CCD analysis demonstrated 8%substrate concentration,1.5%of inoculum along with 10 ppm FeSO4 and a pH of 5.5 in media as optimum conditions for highest enzyme production.The field emission scanning electron microscopic analysis of the treated GS showed structural alterations depicting significant deconstruction caused by B.tequilensis G9.The yield of the partially purified cellulase proteins were found to be 21%revealing molecular mass between 30 and 97 kDa.The enhanced cellulase production by B.tequilensis G9 demonstrated in our study brands its applications in many industrial processes like biorefinery,biofuels,etc.