NISCAIR Online Periodicals Repository Collection: IJBT Vol.05(3) [July 2006]

Biopulping studies using an effluent isolate Cuwularia lunata LW6

Wed, 28 Jun 2006 22:58:59 GMT

Title: Biopulping studies using an effluent isolate Cuwularia lunata LW6

Authors: Narkhede, K P; Vidhale, N N

Abstract: The lignin is unwanted constituent for a pulp and paper manufacturer, which must be removed for getting good quality paper. The aim of bio-delignification of raw material is to make pulping process easier, to save energy requirements, to improve pulp properties and to minimize pollution. The present study aims to find suitability of isolate Curvularia lunata LW6 for biopulping of sugarcane bagasse. The organism was screened from effluent of pulp and paper mill and rested for lignolytic ability. The isolate produced the enzyme lignin peroxidase (3.31 U/mg of protein) and laccase (6.12 UImL). It showed good saprophytic ability (38.14 cm2) on sterile bagasse when supplemented with glucose and yeast extract as cosubstrate. The solid-state fermentation of bagasse for biopulping resulted in loss of weight by 21.66%, while lignin content and kappa number decreased by 44.05% and 40.78%, respectively. The chemical pulping showed 55.25% reduction in kappa number; however, it required high temperature, pressure and alkaline medium. The mutagenesis studies showed slight decrease in cellulase activity of the isolate.

Page(s): 385-388

Efficient Pseudomonas putida for degradation of p-nitrophenol

Wed, 28 Jun 2006 22:58:59 GMT

Title: Efficient Pseudomonas putida for degradation of p-nitrophenol

Authors: Kulkarni, Meenal; Chaudhari, Ambalal

Abstract: Exploration of Pseudomonas putida for controlling environmental (p-nitrophenol) PNP pollution revealed that 0.5 OD inoculum at 600 nm degraded 100 ppm of PNP completely under the ambient conditions within 24 h as established by UV-visible spectrophotometric and TLC analysis of treated broth and confirmed the same by HPLC analysis. An attempt to elucidate the mechanism of PNP degradation indicated that (i) it was oxidative with a stoichiometric release of nitrite, (ii) PNP was converted to hydroquinone, which accumulated in the presence of 2,2'-dipyridyl, (iii) hydroquinone was the first product of ring oxygenation and nitrite removal, as confirmed by TLC and HPLC analysis and (iv) concomitant formation of a keto acid by ring fission, which was confirmed by Rothera's test.

Page(s): 411-415

Integrated biological approach for the enhanced degradation of lindane

Wed, 28 Jun 2006 22:58:59 GMT

Title: Integrated biological approach for the enhanced degradation of lindane

Authors: Nagpal, Varima; Paknikar, K M

Abstract: Lindane is a persistent organic pollutant (POP) and its removal from various environmental compartments is a global priority. In the present study, three lindane degrading bacterial cultures, viz. Pseudoarthrobacter sp., Pseudomonas sp. and Klebsiella sp., were selected from among ten isolates obtained from lindane-exposed soils by enrichment culture technique. The cultures exhibited a maximum lindane degradation efficiency of ~50%, having little significance in bioremediation. However, in the presence of protozoa (ciliates) obtained from the same enrichment culture, lindane degradation efficiency of bacterial cultures increased to the tune of 90-92% with concomitant formation of 1,2,4-trichlorobenzene, a key degradation product. Lindane degradation by the bacterial cultures was also found to get enhanced by 10-15% in the presence of root exudates of lindane-tolerant plants, viz. corn, chili and coriander, even though these plants were unable to uptake any lindane and thus were unsuitable for phytoremediation per se. These data highlight the need for an intensive investigation on (a) bacteria-protozoa interactions for bioremediation of POPs and (b) use of POP-degrading bioinoculants in the rhizospheric soil of resistant plants as a possible alternative, in the absence of a viable conventional remedial option.

Page(s): 400-406

Micropropagation of Azadirachta indica A. Juss. via cotyledonary nodes

Wed, 28 Jun 2006 22:58:59 GMT

Title: Micropropagation of Azadirachta indica A. Juss. via cotyledonary nodes

Authors: Reddy, A Rajasekhar; Bavaji, M; Rao, J V S

Abstract: An efficient protocol for micropropagation of Azadirachta indica A. Juss., a medicinally important plant, has been standardized. Cotyledonary nodes (1 cm long) excised from 15-20 d old in vitro-germinated seedlings were used as explants. The seeds were germinated on half strength MS medium devoid of phytohormones. Cotyledonary nodes were cultured on MS medium supplemented with different concentrations of cytokinins (BA/TDZ/2-ip) and auxins (2,4-D and NAA). Maximum shoot proliferation from single explant was obtained on MS media incorporated with TDZ (1.5 M), 2,4-D (0.5 M), adenine sulphate (40 mg/L), glutamine (100 mg/L) and thiamine HC1 (10 mg/L). In vitro-produced shoots were induced roots on half strength MS medium supplemented with a range of IBA concentrations (0.5-5.0 M). However, the highest frequency of root proliferation was observed on half strength MS medium supplemented with 2.0 M IBA. The regenerants were transferred to field conditions after acclimatization with a success rate of 80%

Page(s): 309-311