Site specific integration of FLP recombinase in BHK-21 cell line.

A binary system for gene activation and site specific integration based on conditional recombination of transfected sequences mediated by FLP recombinase from yeast was implemented in mammalian cells. In several cell lines, FLP rapidly and precisely recombined copies of its specific target sequences to activate an otherwise silent beta-galactosidase reporter gene. Clones of marked cells were generated by excisional recombination within a chromosomally integrated copy of the silent reporters. These clones exhibited intense blue colour with X-Gal staining solution.

Strain improvement studies on production of cephalosporin C from Acremonium chrysogenum ATCC 48272.

Strain development for antibiotic production has been an essential prerequistie for efficient production process. Studies were carried out to produce high antibiotic yield strain by using UV and N-methyl-N1-nitro-nitrosoguanidine (NTG) as mutagens. A superior mutant (PNTG-22) with a productivity of 2.4 time (810-1995 microg/ml higher than, the parent strain was produced.

Characterisation of a new bioactive actinomycete AUB N5/8 from marine sediments.

Actinomycetes were isolated from marine sediments off Machilipatnam coast of Andhra Paradesh by plating on Starch-Casein Agar medium. From which one isolate AUB N5/8 was selected for detailed morphological, cultural, physiological and biochemical studies. The genera encountered were, Streptomycetes. Studies were compared with known strain S. baarinenisis (ISP 5232). It showed enough significant difference to create the status of a separate species for our isolate AUB N5/8. Hence it was designated as Streptomyces kavutarensis Sp.nov.

Production of glycolipids containing biosurfactant by Pseudomonas species.

Microorganisms, that degrade hydrocarbon were isolated and screened for their biosurfactant activity. A total of 68 strains were isolated and tested for their glycolipid activity of which 4 isolates showed good glycolipid activity. Isolate K10 gave the maximum biosurfactant production in medium A (containing kerosene as a sole carbon source) as compared to medium B (containing glucose as a sole carbon source). Characterization of isolate K10 showed that it belongs to Pseudomonas species.

Bioactive actinomycetes from Krishna River sediments of Andhra Pradesh.

Sediment samples from Krishna River at Nagayalanka of Andhra Pradesh, India were investigated as a source of actinomycetes to screen for the production of novel bioactive compounds. During our investigation on fresh water actinomycetes from 5 different river sediment samples, a total of 80 actinomycetes were isolated. Out of these 80 isolates, 30 isolates which showed distinct macromorphological characteristics were selected. The antimicrobial and enzymatic activities were studied for all the 30 isolates. The preliminary study for antimicrobial activity by cross streak method indicated that 16 isolates (53.3%) have excellent antagonistic properties. All these 16 isolates were subjected to detailed submerged fermentation studies. It was observed that 12 isolates (40.0%) exhibited antibacterial activity, 9 isolates (30.0%) showed antifungal activity while 5 isolates (16.6%) showed both antibacterial and antifungal activities. All the 30 isolates were also subjected for the determination of enzymatic activities 25 isolates (83.3%) exhibited amylolytic activity while 27 isolates (90.0%) showed proteolytic activity. Among these isolates, six promising isolates were selected for detailed morphological, cultural, physiological and biochemical studies. It was established that these isolates belong to the Streptomyces genus by virtue of their cell wall composition pattern and were identified as strains of different Streptomyces species like S. rochei, S. alanosinicus, S. erumpens, S. griseoplanus, S. gancidicus and S. nigrogriseolus.

Production and optimization studies of cephalosporin C by solid state fermentation.

Production of cephalosporin C employing a strain, Cephalosporium sp. NCIM 1039 under solid state fermentation was optimized. Different substrates like wheat bran, wheat grains, rice grains, barley and rice bran were studied to optimize the best substrate. Wheat bran showed the highest antibiotic yield. The physical and chemical parameters were optimized. The maximum productivity of cephalosporin C (750 U/g) was achieved by employing wheat bran and with optimized nutritional and process parameters such as potato starch as additive 1% w/w, urea as additive 1% w/w, incubation period of 7 days, incubation temperature at 30 degrees C, inoculum level 10% w/v, moisture content of solid substrate 80% and pH 7.0.

Bioactive rare actinomycetes from indigenous natural substrates of Andhra Pradesh.

This investigation reports the occurrence of bioactive rare actinomycetes from different indigenous natural substrates of Andhra Pradesh. During the course of our investigation on 20 terrestrial soil samples, 5 marine samples and 3 fresh water samples, a total of 92 rare actinomycetes belonging to Micromonospora, Nocardia, Actinomadura and Thermoactinomyces genera were isolated. The antimicrobial and enzymatic activities were studied for all the isolates. The antibacterial and antifungal activities were studied preliminarily by cross-streak method followed by submerged fermentation studies employing standard cup-plate method for the assay. It was found that 34 isolates (36.95%) showed excellent antibacterial activity and 29 isolates (31.52%) showed good antifungal activity. Proteolytic and amylolytic activities were also studied. It was observed that 79 isolates (85.86%) showed proteolytic activity and 75 isolates (81.52%) showed amylolytic activity.

Production of cephalosporin C by immobilized cells of Cephalosporium acremonium.

Cephalosporium acremonium ATCC 48272 cells were immobilized on various adsorbents and in various entrapment matrices. The influence of the incubation period, the best immobilization technique and the optimum concentrations of the selected matrices were investigated. From the results of the repeated batch fermentation in shake flasks, a good level of antibiotic was maintained for a period of about 19 days using 4% calcium alginate and 1% glass wool as entrapment and adsorbent supports, respectively.

Production of alkaline proteinase by a new bacterial strain, Bacillus PE-11.

A new strain of Bacillus sp., Bacillus PE-11 isolated and identified in our laboratory was found to be a potential producer of alkaline proteinase. The production of proteinase was studied in thirteen different reported media to select the optimal production medium. In all the reported media, the medium XII of composition: glucose, 0.2%; peptone, 1.5%; salt solution, 5% (MgSO4. 7H2O, 0.5%; KH2PO4, 0.5%; FeSO4. 7H2O, 0.01%; distilled water make up to 100 ml.) is found to have the highest inducing effect on enzyme production.

A new streptomycete producing diphenyl sulfone antibiotic--S. sulfonensis.

About 359 actinomycetes were isolated from 8 different natural substrates collected from different parts of Andhra Pradesh. The isolates were screened on the basis of their inhibitory effect against test organisms. Finally one potent antibiotic producer was chosen having broad-spectrum activity against Gram-positive and Gram-negative bacteria and it was found to produce a diphenyl sulfone antibiotic. On the basis of morphological, cultural, physiological and biochemical characters, the diphenyl sulfone antibiotic producer was identified as a new species and was designated as S. sulfonensis.

A new variety of Chainia olivacea from marine sediment off Gulf of Mannar.

A new variety of Chainia olivacea was isolated from marine sediment off Gulf of Mannar. The morphological, cultural, physiological and biochemical characters were studied, compared to known species and identified as a new variety of Chainia olivacea. Antibiotic activity of the strain was tested against both Gram positive and Gram negative bacteria as well as fungi and yeasts. Sodium chloride tolerance was also tested.

Production of extracellular protease by Streptomyces fradiae.

A new strain of Streptomyces fradiae, isolated and identified in our laboratory, was found to be a potential producer of protease enzyme. An enzyme yield of 285 P.U./ml. was obtained prior to optimization in a synthetic medium containing potato starch, potassium nitrate and trace salts by shake flask method. The carbon and nitrogen compounds play prominent role in the protease production. The maximum enzyme yield of 930 P.U./ml. (about 3-fold increase) was obtained with all optimum parameters such as pH. 7.0, with 3% jowar starch, 0.5% tryptone, 28 degrees C incubation temperature, with 1:20 medium to flask volume ratio and with 48 hrs. inoculum.

Isolation and characterisation of bioactive actinomycetes from marine sediments.

Actinomycetes (28) were isolated from marine sediments off Madras coast by plating on Starch-Casein Agar medium. After preliminary studies, five isolates which were found to be promising were selected for detailed morphological, cultural, Physiological and biochemical studies. The genera encountered were Streptomycetes. Out of these five isolates, three isolates exhibited very good broad spectrum antibacterial activity. The sodium chloride tolerance of these five isolates was also tested.