Description: This study reports the surface interaction of the chemically modified marine unicellular cyanobacterium Synechococcus elongatus BDU130911 with uranium. The selective functional groups of the control (dead biomass) for binding with uranium in unicellular marine cyanobacteria were identified as carboxyl groups. The adsorption capacity of the biomass in a 1 mM uranium solution was found to be 92% in the control, 85% in the amine-blocked treatments, and 20% in the carboxyl-blocked treatments. The Langmuir isotherm provided a good fit to the data, suggesting a monolayer of uranium adsorption on all the tested biomass. The functional groups involved in the adsorption of uranium by the control and modified biomass were assessed by Fourier transform infrared spectroscopy, energy dispersive X-ray fluorescence and X-ray diffractive analysis. The results of this study identify, carboxyl groups as the dominant anionic functional group involved in uranium adsorption, which validates an ionic interaction between the biomass and uranium, a cationic metal.

Description: Narcissus tazetta L. is a bulbous ornamental plant popular for its notable fragrant flowers which make it the plant of high importance. In spite of its economic value, narcissus is found to be susceptible for a number of diseases borne by fungi, bacteria, nematodes, and viruses. A potyvirus, Cyrtanthus elatus virus - A isolate NBRI16 (CEVA-NBRI16), associated with leaf chlorotic stripe disease of N . tazetta cv. Paperwhite was reported for first time in India from our laboratory based on the partial coat protein gene sequence. In present study, the full-length genomic sequence of CEVA-NBRI16 is determined which consists of 9942 nucleotides, excluding the polyA tail, and encodes a single large polyprotein of 3102 amino acids with the genomic features typical of a potyvirus. It shares highest 93% nucleotide sequence identity and closest phylogenetic relationship with sequences of CEVA-Marijiniup7-1 and CEVA-Marijiniup7-2, both reported from Australia on Cyrtanthus elatus host. The full-length genomic sequence of CEVA from narcissus plant is being reported for the first time from India.

Description: Copra meal is a good source of galactomannan and it s mannooligosaccharides have prebiotic properties. However, limited data are available concerning the ideal requirements for mannan hydrolysis. Thus, optimum hydrolysis conditions for the production of oligosaccharides from copra meal hydrolysate were investigated using response surface methodology. Model validation provided good agreement between experimental results and predicted responses. Maximum oligosaccharide of 14.41 ± 0.09 mg/ml (20 ml) was obtained at an enzyme concentration of 16.52 U/ml, substrate concentration 15% and reaction time 12 h. On a larger scale, this increased to 15.76 ± 0.04 mg/ml (200 ml) and 16.89 mg/ml (2000 ml). Defatted copra meal hydrolysate promoted the growth of beneficial bacteria as lactobacilli and bifidobacteria, while inhibiting pathogens Salmonella serovar Enteritidis S003, Escherichia coli E010, Staphylococcus aureus TISTR 029 and Shigella dysenteriae DMST 1511. Higher yield of oligosaccharides under optimum conditions indicated the potential of this method for production of mannooligosaccharides from copra meal hydrolysate on an industrial scale.

Description: Towards bioremediation of recalcitrant materials like synthetic polymer, soil has been recognized as a traditional site for disposal and subsequent degradation as some microorganisms in soil can degrade the polymer in a non-toxic, cost-effective, and environment friendly way. Microbial functional diversity is a constituent of biodiversity that includes wide range of metabolic activities that can influence numerous aspects of ecosystem functioning like ecosystem stability, nutrient availability, ecosystem dynamics, etc. Thus, in the current study, we assumed that microbial functional diversity could play an important role in polymer degradation in soil. To verify this hypothesis, we isolated soil from five different sites of landfill and examined several microbiological parameters wherein we observed a significant variation in heterotrophic microbial count as well as microbial activities among the soil microcosms tested. Multivariate analysis (principle component analysis) based on the carbon sources utilization pattern revealed that soil microcosms showed different metabolic patterns suggesting the variable distribution of microorganisms among the soil microcosms tested. Since microbial functional diversity depends on both microbial richness and evenness, Shannon diversity index was determined to measure microbial richness and Gini coefficient was determined to measure microbial evenness. The tested soil microcosms exhibited variation in both microbial richness and evenness suggesting the considerable difference in microbial functional diversity among the tested microcosms. We then measured polyhydroxybutyrate (PHB) degradation in soil microcosms after desired period of incubation of PHB in soil wherein we found that soil microcosms having higher functional diversity showed enhanced PHB degradation and soil microcosms having lower functional diversity showed reduced PHB degradation. We also noticed that all the tested soil microcosms showed similar pattern in both microbial functional diversity and PHB degradation suggesting a strong positive correlation ( r  = 0.95) between microbial functional diversity and PHB degradation. Thus, the results demonstrate that microbial functional diversity plays an important role in PHB degradation in soil by exhibiting versatile microbial metabolic potentials that lead to the enhanced degradation of PHB.

Description: Ultrasound-assisted soaking in aqueous ammonia (USAA) pretreatment with 15 wt% aqueous ammonia under low temperature (~ 60 °C) and short-time (〈 12 min) low-frequency (20 kHz, 60–650 W) ultrasound has been investigated for enhancement of enzymatic hydrolysis of corncob. Operational parameters of energy density (2.93–17.07 W/mL) and sonication time (0.34–11.66 min) that affect cellulose recovery, delignification, and sugar recovery yield were studied and optimized. The maximum cellulose recovery, delignification and sugar recovery yield determined at the optimum conditions (energy density 10 W/mL, sonication time 11.66 min) were 83.8, 84.7, and 77.6%, respectively. The corncob pretreated using USAA has a lower hemicellulose content (28.9% vs 31.8%), a slightly lower crystallinity index value (42.7% vs 43.7%), and a larger surface cavity diameter (〉 36 μm vs 〈 20 μm) than that pretreated using soaking in aqueous ammonia (SAA) pretreatment. The USAA pretreatment was proved to be a reliable and effective method for corncob pretreatment.

Description: The objective of this study was to purify, characterize, and phylogenetically and structurally analyze the dextranase produced by the fungus Pochonia chlamydosporia . Dextranase produced by the fungus P. chlamydosporia was purified to homogeneity in two steps, with a yield of 152%, purification factor of 6.84 and specific activity of 358.63 U/mg. Its molecular weight was estimated by SDS-PAGE at 64 kDa. The enzyme presented higher activity at 50 °C and pH 5.0, using 100 mM citrate–phosphate buffer, was inhibited by Ag 1+ , Hg 2+ , Cu 2+ , Mg 2+ , and presented K M of 23.60 µM. Mature dextranase is composed of 585 amino acids residues, with a predicted molecular weight of 64.38 kDa and pI 5.96. This dextranase showed a strong phylogenetic similarity when compared to Trichoderma harzianum dextranase. Its structure consists of two domains: the first composed by 15 β strands, and the second composed by a right-handed parallel β-helix.

Description: Butachlor is a chloroacetamide herbicide used worldwide for controlling weeds in plants of rice, corn, soybean and other crops. In this study, indigenous bacterial species Ammoniphilus sp. JF was isolated from the agricultural fields of Punjab and identified using 16S ribosomal RNA analysis. The bacteria utilized butachlor as the sole carbon source and showed complete degradation (100 mg/L) within 24 h of incubation. Two intermediate products, namely 1,2-benzenedicarboxylic acid, bis(2-methylpropyl) ester and 2,4-bis(1,1-dimethylethyl)-phenol were observed at the end of butachlor degradation. To the best of author’s knowledge, biodegradation of butachlor by indigenous Ammoniphilus sp. JF from the agricultural fields of Punjab has not been reported so far.

Description: In this study, we report the isolation and characterization of the mRNA encoding OPAQUE2 (O2) like TF of finger millet (FM) ( Eleusine coracana) ( EcO2 ). Full-length EcO2 mRNA was isolated using conserved primers designed by aligning O2 mRNAs of different cereals followed by 3′ and 5′ RACE (Rapid Amplification of cDNA Ends). The assembled full-length EcO2 mRNA was found to contain an ORF of 1248-nt coding the 416 amino acids O2 protein. Domain analysis revealed the presence of the BLZ and bZIP-C domains which is a characteristic feature of O2 proteins. Phylogenetic analysis of EcO2 protein with other bZIP proteins identified using finger millet transcriptome data and O2 proteins of other cereals showed that EcO2 shared high sequence similarity with barley BLZ1 protein. Transcripts of EcO2 were detected in root, stem, leaves, and seed development stages. Furthermore, to investigate nitrogen responsiveness and the role of EcO2 in regulating seed storage protein gene expression, the expression profiles of EcO2 along with an α-prolamin gene were studied during the seed development stages of two FM genotypes (GE-3885 and GE-1437) differing in grain protein content (13.8 and 6.2%, respectively) grown under increasing nitrogen inputs. Compared to GE-1437, the EcO2 was relatively highly expressed during the S2 stage of seed development which further increased as nitrogen input was increased. The Ecα - prolamin gene was strongly induced in the high protein genotype (GE-3885) at all nitrogen inputs. These results indicate the presence of nitrogen responsiveness regulatory elements which might play an important role in accumulating protein in FM genotypes through modulating EcO2 expression by sensing plant nitrogen status.

Description: The cyclodextrin glycosyltransferase (CGTase) was used to catalyze the conversion of starch into cyclodextrins (CD) in industry. Improving the activity of CGTase to produce more CD with relative low cost is intensely interesting and has drawn wide attention. Amino acid mutation of His167 into Cys significantly enhanced β-CGTase activity; however, optimization of culture conditions for β-CGTase-H167C remains unclear. To determine this, the medium and culture conditions for β-CGTase-H167C were optimized with response surface methodology. Maximum activity of β-CGTase-H167C was obtained with the medium containing 1.1% corn starch, 4.4% corn steep liquor, 1.1% peptone, 0.02% MgSO 4 ·7H 2 O and 0.1% K 2 HPO 4 ·3H 2 O that were cultured with the initial pH 8.4, incubation temperature at 37.4 °C, with 5% inoculation size and shaking speed at 202 r/min. Under the optimal conditions, the activity of β-CGTase-H167C was up to 4355 U/mL, which is 1.93-fold in comparison with the initial activity. Our results established the promising culture strategy for the production of cyclodextrins by β-CGTase-H167C.

Description: To obtain high-cell-density cultures of Schizochytrium sp. FJU-512 for DHA production, two stages of fermentation strategy were used and carbon/nitrogen ratio, DO and temperature were controlled at different levels. The final dry cell weight, total lipid production and DHA yield in 15 l bioreactor reached 103.9, 37.2 and 16.0 g/l, respectively. For the further study of microbial growth and DHA production dynamics, we established a set of kinetic models for the fed-batch production of DHA by Schizochytrium sp. FJU-512 in 15 and 100 l fermenters and a compensatory parameter n was integrated into the model in order to find the optimal mathematical equations. A modified Logistic model was proposed to fit the cell growth data and the following kinetic parameters were obtained: µ m  = 0.0525/h, X m  = 100 g/l and n  = 4.1717 for the 15 l bioreactor, as well as µ m  = 0.0382/h, X m  = 107.4371 g/l and n  = 10 for the 100 l bioreactor. The Luedeking–Piret equations were utilized to model DHA production, yielding values of α  = 0.0648 g/g and β  = 0.0014 g/g/h for the 15 l bioreactor, while the values of α and β obtained for the 100 l fermentation were 0.0209 g/g and 0.0030 g/g/h. The predicted results compared with experimental data showed that the established models had a good fitting precision and were able to exactly depict the dynamic features of the DHA production process.