NOPR Collection:

In vitro regenerative competence of foliar explants of Cymbidium aloifolium (L.) Sw. and C. iridioides D. Don: Two horticultural important orchids

2013-10-10T16:36:14Z

Title: In vitro regenerative competence of foliar explants of Cymbidium aloifolium (L.) Sw. and C. iridioides D. Don: Two horticultural important orchids Authors: Deb, Chitta Ranjan; Pongener, Aolemla Abstract: In vitro regenerative potentials of foliar explants of Cymbidium aloifolium (L.) Sw. and C. iridioides D. Don. were assessed. About 52% explants of C. aloifolium invoked meristematic loci, followed by shoot buds formation after 65 d of culture on MS medium containing sucrose (3% w/v), α-naphthalene acetic acid (NAA; 6 µM) and benzyl adenine (BA; 9 µM). While 60% of leaf explants of C. iridioides exhibited a similar response on the above basal medium enriched with NAA (9 µM) and BA (3 µM). The better morphogenic response was recorded with explants cultured in upright orientation. The shoot buds developed from the foliar explants of C. aloifolium differentiated into rooted plantlets (12 plantlets/explant) on MS medium containing sucrose (3%) and BA (3 µM); while in case of C. iridioides, about 20 plantlets/explant were developed after 3-4 wk of culture on MS medium fortified with sucrose (3%), casein hydrolysate (100 mg L^-1), coconut water (15%) and NAA (3 µM)+BA (6 µM). The well rooted plantlets of both the species were hardened for 4-6 wk on 1/10^th MS salt solution containing sucrose (1%) but free from plant growth regulators. In the hardening medium, charcoal pieces, brick pieces and chopped mosses (at 1:1:1 ratio) were incorporated as supporting material. After hardening, the regenerated plantlets of both the species were transferred to the community potting mix with 75-80% survivors after two months of transfer under polyhouse condition. Page(s): 402-408

Comparison of biopolymers for immobilization of laccase: Ecotoxicity assessment of azo dye

2013-10-10T16:36:47Z

Title: Comparison of biopolymers for immobilization of laccase: Ecotoxicity assessment of azo dye Authors: Poonkuzhali, K; Palvannan, T Abstract: Laccase from Pleurotus florida was immobilized on agarose/agar/polyacrylamide gel, glass beads and alginate beads. The laccase entrapped agarose gel exhibited 88% of immobilization yield as compared to laccase immobilization on glass bead (72%) and Ba-alginate (50%). The enzyme embodied in agarose gel showed greater storage stability at 16°C as compared to enzyme immobilized on glass beads and alginate method. Among the three substrates, viz., 2,2-azinobis (3-ethylbenzo-thiazoline-6-sulfonate (ABTS), guaiacol and syringaldazine, the laccase oxidation exerted its optimal activity on ABTS. The V_max,K_cat and K_m determined for ABTS were 1.650 µM min⁻¹, 1.160 s⁻¹and 0.0025 mM, respectively. Among the immobilized preparations, laccase entrapped in agarose gel showed high decolorizing ability for Reactive Blue (RB) 172 (83%) within 10 min. The decolorization of RB 172 was confirmed by FTIR analysis. The ecotoxicity assessment of RB 172 decolorization was performed using Allium cepa assay. Page(s): 395-401

Application of Plackett–Burman experimental design and Box and Wilson design to improve broad-spectrum antimicrobial compound

2013-10-13T16:35:40Z

Title: Application of Plackett–Burman experimental design and Box and Wilson design to improve broad-spectrum antimicrobial compound Authors: Sharma, Deepika; Manhas, Rajesh Kumari Abstract: The present study is aimed at optimization of process parameters for production of antimicrobial compound from a potent antibiotic producing Streptomyces isolate. Among a total of 130 actinomycetes, isolate 2A showed antimicrobial activity against all the test organisms including drug resistant bacteria. 16S rRNA gene sequence analysis showed that strain 2A belongs to the genus Streptomyces and exhibited highest 16S rRNA gene sequence similarity (99.8%) with Streptomyces flavotricini NBRC12823^T (AB184173). Comparison of physiological characteristics and DNA-DNA hybridization (manifested 36.7% similarity) with S. flavotricini suggests that 2A is a novel strain (GenBank acc. no. GQ906975). The traditional one-variable-at-a-time optimization strategy and statistically based experimental designs, Plackett-Burman design (PBD) and Box and Wilson design, were applied to provide an efficient approach for optimization. Statistical analysis using PBD demonstrated that KNO₃, K₂HPO₄ and NaCl had significant positive influences on the production. In optimized medium, antimicrobial compound production was increased by 1.5-fold as compared to the basal production medium. In addition, the optimization enhanced the antimicrobial activity spectrum. The crude extract showed ability to inhibit all tested bacteria with MIC ranging from 15.6-125 μg mL^‐1 and MBC from 31.2-500 μg mL^‐1. Page(s): 386-394

Analysis of cow dung microbiota—A metagenomic approach

2013-10-10T16:36:27Z

Title: Analysis of cow dung microbiota—A metagenomic approach Authors: Girija, D; Deepa, K; Xavier, Francis; Antony, Irin; Shidhi, P R Abstract: Cow dung is being used from ancient times in agriculture as it has a significant role in plant growth promotion and plant protection. It is also being used in various religious practices as a purifier. Since only a small fraction of the total microbial diversity can be recovered by culturable methods, a culture independent 16S rDNA approach was taken up for more detailed analysis of cow dung microbiota. Total community DNA was extracted from fresh dung of Brown-Swiss breed and bacterial 16S rRNA genes were subsequently amplified, cloned, sequenced and deposited in GenBank. Bacteria belonging to the phyla Bacteroidetes (38.3%), Firmicutes (29.8%), Proteobacteria (21.3%) and Verrucomicrobia (2%) were identified. Bacteroidetes clones included the genera Bacteroides, Alistipes and Paludibacter; while Clostridium, Ruminococcus, Anaerovorax and Bacillus were predominant in Firmicutes. α- and γ-proteobacterial genera included Acinetobacter, Pseudomonas, Rheinheimera, Stenotrophomonas and Rhodobacter. The Verrucomicrobial clone showed high similarity to Akkermansia. Unculturable bacteria constituted 83.3% in the phylum Bacteroidetes and 87.5% in Firmicutes. All clones under phylum Proteobacteria were culturable bacteria. Eight per cent of the clone library represented previously uncharacterized and unidentified bacteria. Page(s): 372-378