Production of gelatinase enzyme from Bacillus spp isolated from the sediment sample of Porto Novo Coastal sites

Objective: In this study, gelatinase producing bacteria were probed from sediment samples of Porto Novo Coastal sites, India. Screening and identification of potential strain were done followed by optimization of physico-chemical parameters; bulk production and gelatinase extraction were carried out. Methods: For probing of gelatinase potential producer primary and secondary screening was carried out for qualitative and quantitative estimation. Optimization of physico-chemical parameters for improved production of gelatinase enzyme and large scale of gelatinase was produced. Gelatinase precipitation was standardized using different saturation rates of ammonium sulphate from 10 to 100% at 4℃.Results: There were 8 morphologically different gelatinase producing bacteria were initially delved through primary screening tests. Bacillus spp produced maximum gelatinase activity (2.1U/mL) in secondary screening test. Optimizing its abiotic and biotic factors, maximum enzyme activity was achieved at 48h incubation period (2.2U/mL), 2.5 pH (2.5U/mL), 35℃ temperature (2.55U/mL), 0.8% lactose (2.6U/mL), 1.4% gelatin (2.9U/mL) as the ideal carbon source and nitrogen source, 1% salinity (2.9U/mL) and 3ml of inoculum containing 5.6×106/ mL (3.3U/mL). From the optimized factors, bulk production was carried out and saturation rate of 40% ammonium sulphate, precipitated out maximum enzyme with lowered dry weight indicates its enzyme purity and recovered enzyme showed 4.1U/mg of activity. Conclusion: The study revealed that the isolated strain Bacillus spp has its potentiality for industrial scale production and the results will stand as a base line data for the application of gelatinase in future.

Antarctic marine bacterium Pseudoalteromonas sp. KNOUC808 as a source of cold-adapted lactose hydrolyzing enzyme

Psychrophilic bacteria, which grow on lactose as a carbon source, were isolated from Antarctic polar sea water. Among the psychrophilic bacteria isolated, strain KNOUC808 was able to grow on lactose at below 5¨¬C, and showed 0.867 unit of o-nitrophenyl ¥â-D-galactopyranoside(ONPG) hydrolyzing activity at 4¨¬C. The isolate was gram-negative, rod, aerobic, catalase positive and oxidase positive. Optimum growth was done at 20¨¬C, pH 6.8-7.2. The composition of major fatty acids in cell of KNOUC801 was C12:0 (5.48 percent), C12:0 3OH (9.21 percent), C16:0 (41.83 percent), C17:0 ¥ø8 (7.24 percent) and C18:1 ¥ø7 (7.04 percent). All suthese results together suggest that it is affiliated with Pseudoalteromonas genus. The 16S rDNA sequence corroborate the phenotypic tests and the novel strain was designated as Pseudoalteromonas sp. KNOUC808. The optimum temperature and pH for lactose hydrolyzing enzyme was 20¨¬C and 7.8, respectively. The enzyme was stable at 4¨¬C for 7 days, but its activity decreased to about 50 percent of initial activity at 37¨¬C in 7 days.

Advances in studies of antitumor metabolites from marine microorganisms / 中国海洋药物

In the past ten years, many new structurally unique antitumor compounds have been isolated from marine microorganisms. This article summarizes the research advances in antitumor metabolites from marine microorganisms in recent ten years, according to microorganisms species.

Identification of a Marine Bacterium Strain and Characterization of a Novel Functional Gene Cluster Involved in Melanin Biosynthesis / 微生物学通报

A marine bacterium MWYL1,originally isolated from the roots of Spartina anglica growing in a salt marsh near seaside,was identified as a member of the genus of Marinomonas via morphology characterization、physiological test and 16S rDNA sequencing and Blast analysis.The strain was short,rod,gram-negative,grew aerobically and optimally at 28℃.The analysis of 16S rDNA sequence suggests that the sequence similarity values are 97% and 95% with Marinomonas pontica and Marinomonas dokdonensis,respectively.One fosmid clone producing melanin was directly isolated by plating from the genomic library of Marinomonas MWYL1.The novel functional gene cluster involved in melanin biosynthesis was screened after subcloning and sequencing of the 14kb insert in pUC18,further more,the putative functional genes was preminary analyzed using bioinformatics.

Biological Characteristics of Marine Bacterium Strain E18 and the Stability of its Indigo Pigment / 微生物学通报

One strain of Pseudoalteromonas sp. E18 was isolated from the sea mud of Ningbo, Zhejiang. It can produce indigo pigment. The morphological, cultural and biochemical characteristics of the bacterium were studied. The indigo pigment was also extracted. The results showed that the maximum absorption peak of the pigment was at 579nm. The pigment was stable to UV, Na_2SO_3,It was also stable at pH 3～9. The pigment was unstable to the sunlight and high concentration H_2O_2. Temperature of 60℃～80℃ could increase the hue while temperature higher than 90℃ could reduce the hue.

The Growth Characteristic of Antarctic Marine Bacterium BSw10005 / 微生物学通报

The research had screened out an Antarctic marine bacterium BSw10005,which metabolite can prominently inhibit epiphytes contributing to plant pathogens.Bacterium BSw10005 had been cultured with NaCl solution instead of seawater.Using 5L bioreactor,the growth characteristic of BSw10005 have been researched particularly through changing cultivated conditions such as temperature、supply of oxygen and pH,which provide significant information specifically how influenced the growth of bacterium if we change the cultivated conditions.White solid antifungal substances isolated from cultivated marine broth was attained.