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An extracellular low temperature-active alkaline stable peptidase from Acinetobacter sp. MN 12 was purified to homogeneity with a purification fold of 9.8. The enzyme exhibited specific activity of 6,540 U/mg protein, with an apparent molecular weight of 35 kDa. The purified enzyme was active over broad range of temperature from 4 to 60 °C with optimum activity at 40 °C. The enzyme retained more than 75 % of activity over a broad range of pH (7.0–11.0) with optimum activity at pH 9.0. The purified peptidase was strongly inhibited by phenylmethylsulfonyl fluoride, giving an indication of serine type. The K m and V max for casein and gelatin were 0.3529, 2.03 mg/ml and 294.11, 384.61 μg/ml/min respectively. The peptidase was compatible with surfactants, oxidizing agents and commercial detergents, and effectively removed dried blood stains on cotton fabrics at low temperature ranging from 15 to 35 °C. 相似文献
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Mehta Vikrant Meena Jaipal Kasana Harit Munshi Anjana Chander Harish 《Molecular biology reports》2022,49(9):8517-8526
Molecular Biology Reports - An emerging component of Unfolded Protein Response (UPR) pathway, cation transport regulator homolog 1 (CHAC1) has been conferred with the ability to degrade... 相似文献
3.
The bacterial genus Exiguobacterium accommodates many versatile species isolated from diverse environments. Exiguobacterium was described as a genus approximately three decades ago, and now, 17 species, growing over a broad range of temperatures and pH, have been recognized. Various isolates from different niches have been explored for biotechnological and industrial purposes, including enzyme production, bioremediation and degradation of toxic substances released into the environment. Some isolates possess plant growth promoting capabilities, and they are currently being explored for increasing agricultural production. The genome sequences of various strains of this genus have shown the presence of many genes encoding products of importance to agriculture and the environment. In addition, many strains possess stress-responsive genes helping them to colonize and thrive in diverse ecological niches. This review provides a broad view of the versatile genus Exiguobacterium and its potential for applications in agriculture, the environment and industry, as well as the underlying genomic determinants that drive its diversity and adaptability to various extreme environments. 相似文献
4.
A Rapid and Easy Method for the Detection of Microbial Cellulases on Agar Plates Using Gram’s Iodine 总被引:6,自引:0,他引:6
Screening for cellulase-producing microorganisms is routinely done on carboxymethylcellulose (CMC) plates. The culture plates are flooded either with 1% hexadecyltrimethyl ammonium bromide or with 0.1% Congo red followed by 1 M NaCl. In both cases, it takes a minimum of 30 to 40 minutes to obtain the zone of hydrolysis after flooding, and the hydrolyzed area is not sharply discernible. An improved method is reported herein for the detection of extracellular cellulase production by microorganisms by way of plate assay. In this method, CMC plates were flooded with Gram's iodine instead of the reagents just mentioned. Gram's iodine formed a bluish-black complex with cellulose but not with hydrolyzed cellulose, giving a sharp and distinct zone around the cellulase-producing microbial colonies within 3 to 5 minutes. The new method is rapid and efficient; therefore, it can be easily performed for screening large numbers of microbial cultures of both bacteria and fungi. This is the first report on the use of Gram's iodine for the detection of cellulase production by microorganisms using plate assay. 相似文献
5.
Arvind Gulati Pratibha Vyas Praveen Rahi Ramesh Chand Kasana 《Current microbiology》2009,58(4):371-377
A phosphate-solubilizing bacterial strain BIHB 723 isolated from the rhizosphere of Hippophae rhamnoides was identified as Acinetobacter rhizosphaerae on the basis of phenotypic characteristics, carbon source utilization pattern, fatty acid methyl esters analysis, and 16S
rRNA gene sequence. The strain exhibited the plant growth-promoting attributes of inorganic and organic phosphate solubilization,
auxin production, 1-aminocyclopropane-1-carboxylate deaminase activity, ammonia generation, and siderophore production. A
significant increase in the growth of pea, chickpea, maize, and barley was recorded for inoculations under controlled conditions.
Field testing with the pea also showed a significant increment in plant growth and yield. The rifampicin mutant of the bacterial
strain effectively colonized the pea rhizosphere without adversely affecting the resident microbial populations. 相似文献
6.
Vanillin is undoubtedly one of the most popular and widely used flavoring agents in the world. Taking into consideration the
worldwide demand for natural vanillin and its limited supply, alternative routes for its production including biotransformation
are being constantly explored. In this regard, a novel soil bacterium capable of converting isoeugenol to vanillin was isolated
by conventional enrichment process from soils of Ocimum field. On the basis of morphological and physiochemical characteristics and 16S rRNA gene sequence analysis, the isolate
was identified as Pseudomonas chlororaphis CDAE5 (EMBL # AM158279). Vanillin formation was analyzed by gas chromatography (GC), and its structure was confirmed by GC-mass
spectrometry and nuclear magnetic resonance. After 24-h reaction, the vanillin concentration reached 1.2 g L−1 from 10 g L−1 isoeugenol in 20-mL reaction solution at 25°C and 180 rpm. The strain showed potential to be a good candidate for biotechnological
production of vanillin from isoeugenol. Further studies for standardization and optimization for higher yield of vanillin
production needs to be investigated.
†IHBT Communication No. 0676 相似文献
7.
The developmental rates of various life stages ofRhagoletis completa Cresson (Diptera: Tephritidae) were determined in the laboratory at seven different constant temperatures: 8, 12, 16, 20,
24, 28, and 32±1°C, RH 80±10%, photoperiod L 16∶D8. Preoviposition developmental rate was fastest at 28°C (10±1 days, mean±SD)
and slowest at 12°C (26±1 days). About 83% of the females deposited eggs at 20 and 24°C and only 25% oviposited at 32°C. Females
laid the highest number of eggs at 24°C and the lowest at 8°C. Egg development increased with increasing temperatures up to
28°C, then declined. The fastest egg development was noticed at 28°C (55±1 h) and slowest at 8°C (389±2 h). Over 90% egg hatch
was observed at temperatures between 12 and 32°C, but decreased to 73% at 8°C. Larval development was fastest also at 28°C
(20±0.2 days). Over 65% pupation was recorded at 20 and 24°C, but decreased to 15% at 32°C and 12% at 8°C. Pupal development
was most rapid at 24°C (53±1 days) and slowest at 8°C (162±2 days). More than 70% of adult emergence was noticed in treatments
between 16 and 24°C but decreased to 20% at 8°C. Based on a linear regression model of temperature-development rate relationship,
the lower developmental thresholds were determined to be 6.6, 5.3, 2.9, and 5°C for preoviposition, egg, larval, and pupal
stages, respectively. Based on a non-linear developmental rate model, the upper developmental thresholds were 34°C for preoviposition,
egg, and larval stages and 30°C for pupal stage. 相似文献
8.
Out of nine psychrotrophic bacterial strains isolated from cold environments of the Western Himalayas, SKPB5 was selected
for protease purification and characterization because it had the largest zone of clearance on plate assay. On the basis of
the phenotypic and biochemical characterization and 16S rRNA gene-sequencing studies, isolate was identified as Exiguobacterium sp. SKPB5. The protease was purified near to homogeneity with a purification fold of 7.1, and its molecular weight was determined
to be 36 kDa. The enzyme exhibited maximum stability at 50°C and an optimal pH of 8.0. Metal ions Mg2+, Ca2+, Zn2+, and Mn2+ enhanced the enzyme activity, whereas Cu2+ had no effect. Phenylmethanesulfonyl fluoride and ethylenediaminetetraacetic acid did not show any effect on the activity
of the enzyme, whereas a 20% increase in activity was observed when it was incubated in presence of reducing agents such as
β-mercaptoethanol and dithiothreitol. This suggests that the protease isolated from psychrotrophic Exiguobacterium sp. SKPB5 belongs to the cysteine family. The results highlight the relevance of unexplored microbes from cold environments
of Western Himalayas for the isolation of protease enzymes active at wide range of temperature and pH. 相似文献
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