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Petrochemical plastics have become a basic requisite in today's world. Their production has increased dramatically since the last few decades owing to the increase in their demand. Sustainable green plastics produced from polylactic acid have proven to be an alternative to conventional plastics pertaining to their tendency of biodegradability; they are disintegrated by microorganisms and are utilized as carbon sources by plants and other primitive organisms. Rhizopus species is appropriate for the biosynthesis of lactic acid, which is the basic raw material of polylactic acid could be obtained from lignocellulosic biomass since the fungus has the ability to grow on and ferment various carbon sources like cellulose, starch and so on. This research paper deals with the effective biosynthesis of lactic acid from Paper Sludge (PS) through the method of simultaneous saccharification and fermentation (SSF), along with the optimization of various parameters like temperature, pH and initial substrate concentration. An economical and an alternative methodology was opted to prepare cellulase enzyme necessary for the fermentation process, considering the fact that commercially available cellulase are exorbitant. Various combinations of the above enzymes were tested to determine the optimal cellulase cocktail suitable for these conditions. Finally, lactic acid productivity of 27 g/L was achieved when using a blended cellulase cocktail at 50:50 proportion of commercial and fabricate cellulase using a feed concentration of 75 g/L at 40 °C and 6 pH after144 hr by SSF. [ABSTRACT FROM AUTHOR]

Abstract Background High salinity (1–10% w/v) of tannery wastewater makes it difficult to be treated by conventional biological treatment. Salt tolerant microbes can adapt to these saline conditions and degrade the organics in saline wastewater. Results Four salt tolerant bacterial strains isolated from marine and tannery saline wastewater samples were identified as Pseudomonas aeruginosa, Bacillus flexus, Exiguobacterium homiense and Staphylococcus aureus. Growth factors of the identified strains were optimized. Tannery saline wastewater obtained from a Common Effluent Treatment Plant (CETP) near Chennai (southern India) was treated with pure and mixed consortia of four salt tolerant bacterial strains. Experiments with optimized conditions and varying salt content (between 2 and 10% (w/v) were conducted. Salt inhibition effects on COD removal rate were noted. Comparative analysis was made by treating the tannery saline wastewater with activated sludge obtained from CETP and with natural habitat microbes present in raw tannery saline wastewater. Conclusion Salt tolerant bacterial mixed consortia showed appreciable biodegradation at all saline concentrations (2%, 4%, 6%, 8% and 10% w/v) with 80% COD reduction in particular at 8% salinity level the consortia could be used as suitable working cultures for tannery saline wastewater treatment.

Leucas aspera is a high value medicinal plant in India, Java, Mauritius and Philippines. The effects of plant growth regulators effects on in vitro callus biomass accumulation and root enhancement were assessed using leaf and stem explants. Leaf and stem explants were cultured on Murashige and Skoog basal medium supplemented with different concentrations of auxins and cytokinins. The highest amount of callus biomass accumulation was observed on leaf explants. Comparisons between stem and leaf explants indicated that leaf explants showed the greatest callus formation. Greatest callus formation was observed on NAA (2 mg L−1) (79.22%), followed by 2,4-D (2.0 mg L−1) (70.11%) and IBA (2.0 mg L−1) showed the least formation (36.42%). Maximum callus formation was observed on stem explants; these showed 60.70% from 2,4-D (2 mg L−1), NAA (2 mg L−1) showed 40.16%, and far less was obtained on IBA (31.60%). The greatest root formation (75.32%) was obtained on IBA (2 mg L−1) and the number of roots per shoot obtained was 26.55%; IAA (2 mg L−1) showed 66.82% root formation and the number of roots obtained was 21.22%; NAA (2 mg L−1) showed 54.33% root formation. In conclusion, root enhancement increased best under dark conditions, the conditions most suitable for regeneration of large numbers of high value clonal plants for commercial production and isolation of bioactive compounds. [ABSTRACT FROM AUTHOR]