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| Wei,Shiping; Cui,Hongpeng; Jiang,Zhenglong; Liu,Hao; He,Hao; Fang,Nianqiao. |
| Biomineralization is a known natural phenomenon associated with a wide range of bacterial species. Bacterial-induced calcium carbonate precipitation by marine isolates was investigated in this study. Three genera of ureolytic bacteria, Sporosarcina sp., Bacillus sp. and Brevundimonas sp. were observed to precipitate calcium carbonate minerals. Of these species, Sporosarcina sp. dominated the cultured isolates. B. lentus CP28 generated higher urease activity and facilitated more efficient precipitation of calcium carbonate at 3.24 ± 0.25 × 10−4 mg/cell. X-ray diffraction indicated that the dominant calcium carbonate phase was calcite. Scanning electron microscopy showed that morphologies of the minerals were dominated by cubic, rhombic and polygonal... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Calcium carbonate precipitation; Calcite; Marine bacteria; Urease. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822015000200455 |
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| Wei,Shiping; Hurley,James; Jiang,Zhenglong; Wang,Siwen; Wang,Yuanyuan. |
| The use of the filamentous fungus, Ashbya gossypii, to improve riboflavin production at an industrial scale is described in this paper. A riboflavin overproducing strain was isolated by ultraviolet irradiation. Ten minutes after spore suspensions of A. gossypii were irradiated by ultraviolet light, a survival rate of 5.5% spores was observed, with 10% of the surviving spores giving rise to riboflavin-overproducing mutants. At this time point, a stable mutant of the wild strain was isolated. Riboflavin production of the mutant was two fold higher than that of the wild strain in flask culture. When the mutant was growing on the optimized medium, maximum riboflavin production could reach 6.38 g/l. It has even greater promise to increase its riboflavin... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Riboflavin; Ashbya gossypii; Ultraviolet irradiation; Medium optimization. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822012000200003 |
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| Wei,Shiping; Jiang,Zhenglong; Liu,Hao; Zhou,Dongsheng; Sanchez-Silva,Mauricio. |
| Microbiologically induced deterioration (MID) causes corrosion of concrete by producing acids (including organic and inorganic acids) that degrade concrete components and thus compromise the integrity of sewer pipelines and other structures, creating significant problems worldwide. Understanding of the fundamental corrosion process and the causal agents will help us develop an appropriate strategy to minimize the costs in repairs. This review presents how microorganisms induce the deterioration of concrete, including the organisms involved and their colonization and succession on concrete, the microbial deterioration mechanism, the approaches of studying MID and safeguards against concrete biodeterioration. In addition, the uninvestigated research area of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Microbial deterioration; Concrete corrosion; Biogenic sulfuric acid. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822013000400001 |
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