Ganesh D. Saratale

Enzymatic hydrolysis and characterization of waste lignocellulosic biomass produced after dye bioremediation under solid state fermentation.

Sugarcane bagasse (SCB) adsorbes 60% Reactive Blue172 (RB172). Providensia staurti EbtSPG able to decolorize SCB adsorbed RB172 up to 99% under solid state fermentation (SSF). The enzymatic saccharification efficiency of waste biomass after bioremediation of RB172 process (ddSCB) has been evaluated. The cellulolyitc crude enzyme produced by Phanerochaete chrysosporium used for enzymatic hydrolysis of native SCB and ddSCB which produces 0.08 and 0.3 g/L of reducing sugars respectively after 48 h of incubation. The production of hexose and pentose sugars during hydrolysis was confirmed by HPTLC. The effect of enzymatic hydrolysis on SCB and ddSCB has been evaluated by FTIR, XRD and SEM analysis. Thus, during dye biodegradation under SSF causes biological pretreatment of SCB which significantly enhanced its enzymatic saccharification. Adsorption of dye on SCB, its bioremediation under SSF produces wastes biomass and which further utilized for enzymatic saccharification for biofuel production.

Biodegradation of hazardous triphenylmethane dye methyl violet by Rhizobium radiobacter (MTCC 8161)

Rhizobium radiobacter MTCC 8161 completely decolorized methyl violet (10 mg l–1) within 8 h both at static and shaking conditions. The decolorization time increased with increasing dye concentration. The effect of different carbon and nitrogen sources on the decolorization of methyl violet was studied. The maximum decolorization was observed in the presence of sucrose (1%) and urea (1%). UV‐Visible, HPLC and FTIR analysis of extracted products confirmed biodegradation of methyl violet. The significant increase in the activities of lignin peroxidase and aminopyrine N‐demethylase in the cells obtained after decolorization indicated involvement of these enzymes in the decolorization process. In addition to methyl violet, this strain also shows an ability to decolorize various industrial dyes, (red HE7B, yellow 4G, blue 2B, navy blue HE22, red M5B and red HE3B). (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Oxidative stress response in dye degrading bacterium Lysinibacillus sp. RGS exposed to Reactive Orange 16, degradation of RO16 and evaluation of toxicity

Lysinibacillus sp. RGS degrades sulfonated azo dye Reactive Orange 16 (RO16) efficiently. Superoxide dismutase and catalase activity were tested to study the response of Lysinibacillus sp. RGS to the oxidative stress generated by RO16. The results demonstrated that oxidative stress enzymes not only protect the cell from oxidative stress but also has a probable role in decolorization along with an involvement of oxidoreductive enzymes. Formation of three different metabolites after degradation of RO16 has been confirmed by GC-MS analysis. FTIR analysis verified the degradation of functional groups of RO16, and HPTLC confirmed the removal of auxochrome group from the RO16 after degradation. Toxicity studies confirmed the genotoxic, cytotoxic, and phytotoxic nature of RO16 and the formation of less toxic products after the treatment of Lysinibacillus sp. RGS. Therefore, Lysinibacillus sp. RGS has a better perspective of bioremediation for textile wastewater treatment.

Biohydrogen from Renewable Resources

Abstract The world’s energy markets rely heavily on fossil fuels (such as coal, petroleum, and natural gases). However, due to increasing energy demands, depleting reserves of fossil fuels, and increasing negative effects on the environment (e.g., global warming and climate changes), as well as growing political instability in oil-producing nations, the world is facing a major energy threat that needs to be solved by virtue of alternative energy sources utilizing renewable resources. The only natural, renewable carbon resource known with large enough capacity to substitute for fossil fuels is biomass. Thus, energy from biomass is considered to be one of the most promising alternatives to fossil fuels. Among the existing biomass energy/biofuels, biohydrogen has received considerable attention as it is clean, renewable, has a high energy content, and does not contribute to the greenhouse effect. Biomass is projected as a virtually eternal raw material for hydrogen (H2) production; however, the main bottleneck is the low hydrogen yield arising from poor efficiency on direct microbial assimilation of biomass. Therefore, technologies leading to more efficient and commercially viable production of biohydrogen from biomass and other renewable resources are urgently demanded. This chapter sheds light on some of the practical approaches of fermentative H2-generating processes utilizing a variety of biomass and renewable resources as substrate. This chapter also emphasizes biohydrogen production technology that could maximize hydrogen yield by designing efficient bioprocess integration and energy and waste minimization. Improving the hydrolysis of biomass has been recognized as a key step toward biohydrogen production. Considerable research efforts made on improving the pretreatment and hydrolysis of biomass materials are also addressed. Emphasis is given to discussion of the process based on important operating factors involved and to delineation of some of the process limitations. The aim of this chapter is to provide rapidly expanding information on biohydrogen production from renewable resources and to offer clues and possibilities for enhancing the performance of natural waste utilization and dark fermentative hydrogen production to resolve issues related to food security, climate change, energy security, and clean development in the future.

Study of mixed function oxidase system in Aspergillus ochraceus (NCIM 1146)

Aspergillus ochraceus (NCIM-1146) has shown the ability to degrade cholesterol, camphor and naphthalene, when 96 h grown mycelium incubated in medium containing these organic compounds. Presence of higher level of electron transport components and biotransformation enzyme activity were observed in Aspergillus ochraceus, when grown in potato dextrose medium for 96 h. The enzyme activity preferred NADPH as a cofactor and shows inhibition in the presence of CO, indicating cytochrome P-450 mediated reactions. A significant increase in the levels of electron transport components and biotransformation enzyme activity were observed in presence of different inducers (viz. cholesterol, camphor, naphthalene, veratrole, phenobarbital, n-hexane, kerosene and saffola oil) when compared with mycelium incubated in same way with similar conditions for 2 min incubation. Analyses of the products of cholesterol and camphor using HPLC and GCMS confirm the degradation of these compounds.