NOPR Collection:

Alginate immobilization of Spirulina platensis for waste water treatment

2001-08-01T00:00:00Z

Title: Alginate immobilization of Spirulina platensis for waste water treatment Authors: Patnaik, Susmita; Sarkar, Rekha; Mitra, Arunabha Abstract: Immobilization of cyanobacterium Spirulina platensis in sodium alginate (1.5 %) gave the best quality of bead and 15- 16 beads were formed per mL of aqueous solution of alginate. The immobilized cells were used in a batch process for treatment of diluted sewage. After 8 days, 95 % of BOD₅, 77 % of COD, 90 % of ammonia, and 94 % of TSS were removed. Page(s): 824-826

Symbiotic effectiveness of bacteriocin producing and non-producing strains of Rhizobium in green gram (Vigna radiata)

2001-08-01T00:00:00Z

Title: Symbiotic effectiveness of bacteriocin producing and non-producing strains of Rhizobium in green gram (Vigna radiata) Authors: Goel, A K; Sindhu, S S; Dadarwal, K R Abstract: Rhizobium strains nodulating green gram [Vigna radiata (L.) Wilczek] were found to produce bacteriocin on modified Bergersen' s medium and inhibited the growth of homologous Rhizobium strains. Four bacteriocin producing and four bacteriocin non-producing strains were compared for their effect on nodulation, in planta nitrogenase activity and plant dry weight of green gram. The bacteriocin producers formed more nodules in comparison to non-bacteriocin producers. However, the symbiotic effectiveness of bacteriocin producers was less in terms of plant dry weight in comparison to nonbacteriocin producers. Page(s): 821-823

Genetics of thermotolerance in ciprofioxacin resistant mutant of Rhizobium leguminosarum bv phaseoli

2001-08-01T00:00:00Z

Title: Genetics of thermotolerance in ciprofioxacin resistant mutant of Rhizobium leguminosarum bv phaseoli Authors: Singh, R K Abstract: A ciprotloxacin resi stant mutant (Cf^R) of Rhizobium leguminossarum by phaseoli USDA 2695 which nodulates common bean plants (Phaseolus vulgaris L) was isolated after nitrous acid mutagenesis. Another mutant resistant to nalidixic acid (Nal^R) was isolated spontaneously. Both mutants showed thermotolerance as evident by their ability to grow at elevated (40°C) temperature, although the wild type (USDA 2695) failed to grow at this temperature. Transformation and plasmid curing experiments suggested the gene(s) controlling thermotolerance (TrR) and resistance to nalidixic acid or cipro tloxacin were located on the main chromosome and not on the plasmids. High frequency of co-transfer of Tr^R-Cr^R and Tr^R-Nal^Rduring transformation experiments indicated a close association of these gene(s). Role of DKA gyrase and supercoiling in these thermololerant mutants has been discussed. Page(s): 818-820

Chronic toxicity bioassay and effect of endosulfan, HCH, copper and zinc on the survival and intermoult duration of larvae of mangrove crab Macrophthalmus erato De Man

2001-08-01T00:00:00Z

Title: Chronic toxicity bioassay and effect of endosulfan, HCH, copper and zinc on the survival and intermoult duration of larvae of mangrove crab Macrophthalmus erato De Man Authors: Kannupandi, T; Pasupathi, K; Soundarapandian, P Abstract: The effects of insecticides (endosulfan, HCH) and heavy metals (copper and zinc) were studied on survival and duration of the moult cycle of larvae and megalopa of a common mangrove crab, Macrophthalmus erato, that inhabits Pitchavaram mangroves, southeast coast of India. In chronic toxicity test, percentage of survival from hatchling to megalopa stage at different concentrations of endosulfan (0.048 to 0.36 µg/L), HCH (0.32 to 2.4 μg/L), copper (9.0 to 67.5 μg/L) and zinc (15.2 to 139.0 μg/L) were 6, 12,8 and 12 respectively. Endosulfan, HCH, copper and zinc considerably increased the total period in development from first zoea to megalopa stage from 18 days in the control to 23, 21, 20 and 22 days in the treated specimens. It is concluded that concentrations well below the observed chronic concentrations, may prove to be more deleterious to larva of this species in natural environment leading to reduction in the success of recruitment to the adult population. Page(s): 814-817