Base de dados : LILACS
Pesquisa : B03.440.400.425.622 [Categoria DeCS]
Referências encontradas : 5 [refinar]
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Id: biblio-1087706
Autor: Zhang, Zheng; Yu, Yong-xiang; Wang, Yin-geng; Wei, Xin-xian; Liao, Mei-jie; Rong, Xiao-jun; Chen, Jing.
Título: Development of a new protocol for freeze-drying preservation of Pseudoalteromonas nigrifaciens and its protective effect on other marine bacteria
Fonte: Electron. j. biotechnol;44:1-5, Mar. 2020. graf, tab.
Idioma: en.
Projeto: The Key Projects of Science and Technology Innovation of Shandong Province; . Special Founds of Innovation-driven Development of Guangxi; . Central Public-interest Scientific Institution Basal Research Fund, Yellow Sea Fisheries Research Institutes, CAFS.
Resumo: Background: Freeze-drying is known as one of the best methods to preserve bacterial strains. Protectant is the key factor affecting the survival rate of freeze-dried strains. In addition, salinity, bacterial suspension concentration, drying time, and other factors can also affect the survival rate of strains to varying degrees. At present, there are relatively few studies on freeze-drying preservation of marine bacteria. In the present study, we performed the freeze-drying protectant screening and optimized the preservation conditions for Pseudoalteromonas nigrifaciens, which is widely distributed in marine environment. The protective effects of the screened protectants were verified by 18 other marine bacterial strains. Results: The results indicated that the combination of 5.0% (w/v) lactose, 5.0% (w/v) mannitol, 5.0% (w/v) trehalose, 10.0% (w/v) skim milk powder, 0.5% (w/v) ascorbic acid and 0.5% (w/v) gelatin was the best choice for the preservation of P. nigrifaciens. The suggested salinity and concentration of initial cell suspension were 10 g/L NaCl and 1.0 × 109 CFU/mL, respectively. Furthermore, stationary-phase cells were the best choice for the freeze-drying process. The highest survival rate of P. nigrifaciens reached 52.8% when using 5­10% (w/v) skim milk as rehydration medium. Moreover, the other 18 marine strains belonging to Pseudoalteromonas, Vibrio, Photobacterium, Planomicrobium, Edwardsiella, Enterococcus, Bacillus, and Saccharomyces were freezedried under the abovementioned conditions. Their survival rates were 2.3­95.1%. Conclusion: Collectively, our results supported that the protectant mixture and parameters were beneficial for lyophilization of marine bacteria
Descritores: Preservação Biológica/métodos
Pseudoalteromonas/fisiologia
Liofilização/métodos
-Trealose/química
Sobrevivência Celular
Fenômenos Fisiológicos Bacterianos
Dissacarídeos/química
Viabilidade Microbiana
Salinidade
Lactose/química
Manitol/química
Responsável: CL1.1 - Biblioteca Central


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Id: biblio-1022610
Autor: Xiao, Qiong; Zhu, Yanbing; Li, Jiajia; Wu, Changzheng; Ni, Hui; Xiao, Anfeng.
Título: Fermentation optimization and enzyme characterization of a new ι-Carrageenase from Pseudoalteromonas carrageenovora ASY5
Fonte: Electron. j. biotechnol;32:26-34, Mar. 2018. graf, tab.
Idioma: en.
Projeto: University-Enterprise Cooperation of Fujian Province; . Public Science and Technology Research Funds Projects of Ocean; . Major Science and Technology Programs and Special Topics of Fujian Province; . Key Program of Science Foundation of Fujian Province.
Resumo: Background: A new ι-carrageenase-producing strain was screened from mangroves and authenticated as Pseudoalteromonas carrageenovora ASY5 in our laboratory. The potential application of this new strain was evaluated. Results: Medium compositions and culturing conditions in shaking flask fermentation were firstly optimized by single-factor experiment. ι-Carrageenase activity increased from 0.34 U/mL to 1.08 U/mL after test optimization. Optimal fermentation conditions were 20°C, pH 7.0, incubation time of 40 h, 15 g/L NaCl, 1.5% (w/v) yeast extract as nitrogen source, and 0.9% (w/v) ι-carrageenan as carbon source. Then, the crude ι-carrageenase was characterized. The optimum temperature and pH of the ι-carrageenase were 40°C and 8.0, respectively. The enzymatic activity at 35­40°C for 45 min retained more than 40% of the maximum activity. Meanwhile, The ι-carrageenase was inhibited by the addition of 1 mmol/L Cd2+ and Fe3+ but increased by the addition of 1 mmol/L Ag+, Ba2+, Ca2+, Co2+, Mn2+, Zn2+, Fe2+, and Al3+. The structure of oligosaccharides derived from ι-carrageenan was detected using electrospray ionization mass spectrometry (ESI-MS). The ι-carrageenase degraded ι-carrageenan, yielding disaccharides and tetrasaccharides as main products. Conclusions: The discovery and study of new ι-carrageenases are beneficial not only for the production of ι-carrageenan oligosaccharides but also for the further utilization in industrial production.
Descritores: Proteínas de Bactérias/metabolismo
Pseudoalteromonas/enzimologia
Glicosídeo Hidrolases/metabolismo
-Oligossacarídeos/biossíntese
Temperatura
Carbono/metabolismo
Carragenina/biossíntese
Espectrometria de Massas por Ionização por Electrospray
Fermentação
Concentração de Íons de Hidrogênio
Hidrólise
Nitrogênio/metabolismo
Responsável: CL1.1 - Biblioteca Central


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Texto completo SciELO Brasil
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Id: lil-755831
Autor: Li, Jiang; Hu, Qiushi; Li, Yuquan; Xu, Yuan.
Título: Purification and characterization of cold-adapted beta-agarase from an Antarctic psychrophilic strain
Fonte: Braz. j. microbiol;46(3):683-690, July-Sept. 2015. tab, ilus.
Idioma: en.
Projeto: Public Science and Technology Research Funds Project of Ocean; . Chinese Polar Environment Comprehensive Investigation & Assessment Programs; . Shandong Province Young and Middle-Aged Scientists Research Awards Fund; . Basic Scientific Research Funds of FIO, SOA.
Resumo:

An extracellular β-agarase was purified from Pseudoalteromonas sp. NJ21, a Psychrophilic agar-degrading bacterium isolated from Antarctic Prydz Bay sediments. The purified agarase (Aga21) revealed a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with an apparent molecular weight of 80 kDa. The optimum pH and temperature of the agarase were 8.0 and 30 °C, respectively. However, it maintained as much as 85% of the maximum activities at 10 °C. Significant activation of the agarase was observed in the presence of Mg2+, Mn2+, K+; Ca2+, Na+, Ba2+, Zn2+, Cu2+, Co2+, Fe2+, Sr2+ and EDTA inhibited the enzyme activity. The enzymatic hydrolyzed product of agar was characterized as neoagarobiose. Furthermore, this work is the first evidence of cold-adapted agarase in Antarctic psychrophilic bacteria and these results indicate the potential for the Antarctic agarase as a catalyst in medicine, food and cosmetic industries.

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Descritores: Adaptação Fisiológica/fisiologia
Ágar/metabolismo
Glicosídeo Hidrolases/metabolismo
Pseudoalteromonas/enzimologia
-Regiões Antárticas
Adaptação Fisiológica/genética
Proteínas de Bactérias/metabolismo
Temperatura Baixa
Dissacarídeos/biossíntese
Sedimentos Geológicos/microbiologia
Glicosídeo Hidrolases/isolamento & purificação
Hidrólise
/genética
RNA, RIBOSOMAL, ABNORMALITIES, MULTIPLES/genética
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME


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Texto completo SciELO Brasil
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Id: lil-656691
Autor: López, Ruth; Monteón, Víctor; Chan, Ernesto; Montejo, Rubí; Chan, Manuel.
Título: Oxygen limitation favors the production of protein with antimicrobial activity in Pseudoalteromonas sp
Fonte: Braz. j. microbiol;43(3):1206-1212, July-Sept. 2012. ilus, graf.
Idioma: en.
Resumo: This study examined the effect of dissolved oxygen concentration on the production of biomass and metabolites with antimicrobial activity of Pseudoalteromonas sp cultured at 0, 150, 250, or 450 revolutions per minute (rev. min-1). Dissolved oxygen (D.O) was monitored during the fermentation process, biomass was quantified by dry weight, and antimicrobial activity was assessed using the disk diffusion method. The bacterium Pseudoalteromonas reached similar concentration of biomass under all experimental agitation conditions, whereas antimicrobial activity was detected at 0 and 150 rev. min-1 registering 0% and 12% of D.O respectively corresponding to microaerophilic conditions. Antibiotic activity was severely diminished when D.O was above 20% of saturation; this corresponded to 250 or 450 rev. min-1. SDS-PAGE electrophoresis revealed a protein with a molecular weight of approximately 80 kilodaltons (kDa) with antimicrobial activity. Pseudoalteromonas is capable of growing under oxic and microaerophilic conditions but the metabolites with antimicrobial activity are induced under microaerophilic conditions. The current opinion is that Pseudoalteromonas are aerobic organisms; we provide additional information on the amount of dissolved oxygen during the fermentation process and its effect on antimicrobial activity.
Descritores: Antibacterianos/análise
Biomassa
Fermentação
Metabolismo
Oxigênio/metabolismo
Pseudoalteromonas/metabolismo
-Eletroforese Descontínua
Bactérias Aeróbias Gram-Negativas
Métodos
Métodos
Tipo de Publ: Estudo de Avaliação
Responsável: BR32.1 - Serviço de Biblioteca e Informação Biomédica


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Id: lil-634577
Autor: Vázquez, S.C.; Hernández, E.; Mac Cormack, W.P..
Título: Extracellular proteases from the Antarctic marine Pseudoalteromonas sp. P96-47 strain / Proteasas extracelulares de la cepa marina antártica Pseudoalteromonas sp. P96-47
Fonte: Rev. argent. microbiol;40(1):63-71, ene.-mar. 2008. ilus, graf, tab.
Idioma: en.
Projeto: UBACyT; . IAA.
Resumo: The extracellular protease-production capacity of 33 bacterial isolates taken from marine biotopes in King George Island, Antarctica, was evaluated in liquid cultures. The P96-47 isolate was selected due to its high production capacity and was identified as Pseudoalteromonas sp. The optimal growth temperature was 20 °C and the optimal for protease production was 15 °C. Proteases were purified from culture supernatants, developing a multiple-band profile in zymograms. They were classified as neutral metalloproteases and worked optimally at 45 °C with an Eact of 47 kJ/ mol. Their stability was higher at neutral pH, retaining more than 80% of activity at pH 6-10 after 3 h incubation at 4 °C. After 90 min incubation at 40 and 50 °C, the percentages of residual activities were 78% and 44%. These results contribute to the basic knowledge of Antarctic marine proteases and also help evaluate the probable industrial applications of P96-47 proteases.

La capacidad productora de proteasas extracelulares de 33 aislamientos bacterianos tomados de biotopos marinos en la Isla Rey Jorge, Antártida, fue evaluada en cultivo líquido. El aislamiento P96-47 fue seleccionado debido a su alta capacidad productora y fue identificado como Pseudoalteromonas sp. La temperatura óptima de crecimiento fue de 20 °C y la de producción de 15 °C. Las proteasas fueron purificadas a partir del sobrenadante de cultivo, y en los zimogramas desarrollaron un perfil de múltiples bandas. Estas proteasas fueron clasificadas como metaloproteasas neutras y se observó que trabajan óptimamente a 45 °C, con una Eact de 47 kJ/ mol. Su estabilidad fue superior a pH neutro y retuvieron más del 80% de su actividad a pH 6-10 después de 3 h de incubación a 4 °C. Luego de 90 min de incubación a 40 y 50 °C, las actividades residuales fueron 78% y 44%, respectivamente. Los resultados que se presentan en este trabajo contribuyen al conocimiento básico de las proteasas marinas antárticas y también a evaluar las probables aplicaciones industriales de las proteasas de P96-47.
Descritores: Peptídeo Hidrolases/biossíntese
Pseudoalteromonas/enzimologia
-Água do Mar/microbiologia
Microbiologia da Água
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: AR1.2 - Instituto de Investigaciónes Epidemiológicas



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