Maintenance of strains of Campylobacter jejuni in laboratories after use of cryoprotectors and pre-treatment of stress / Manutenção de cepas de Campylobacter jejuni em laboratório após uso de crioprotetores e pré-tratamento de estresse

This study evaluated the feasibility and the production of transcripts of sodB, p19, ciaB and dnaJ genes in strains of Campylobacter jejuni ATCC 33291, NCTC 11351, and 2383 IAL stored in whole UHT milk and or neopepton + 12% glycerol, submitted or not to pre-treatments at 4°C or 10°C for 30 minutes. The analyzes were performed immediately after freezing in liquid nitrogen (day 0) and after maintenance for 30, 60, and 90 days at -20ºC. The viability was evaluated by the traditional culture method and the production of transcripts by the RT-PCR technique. The quantification was only possible on the first day of analysis (day 0) and presented a mean of 3.0 x 107 CFU, and in the other periods of storage the strains presented confluent growth, not allowing their enumeration. The results indicated that whole UHT milk was more adequate for cryopreservation than the use of neopepton + 12% glycerol. The use of pre-treatments combined with the use of UHT milk as a cryoprotective medium stabilized the cells in order to transcribe the ciaB, dnaJ, sodBand p19 genes in the strains maintained under -20 ° for 30 to 60 days, indicating that they are more suitable methods for the maintenance of strains in the laboratory.

Este estudo avaliou a viabilidade e a produção de transcritos dos genes sodB, p19, ciaB e dnaJ em cepas de Campylobacter jejuni ATCC 33291, NCTC 11351 e 2383 IAL armazenadas em leite integral UHT e / ou neopeptona + 12% glicerol, submetidas ou não a pré-tratamentos a 4°C ou 10°C durante 30 minutos. As análises foram realizadas imediatamente após o congelamento em nitrogênio líquido (dia 0) e após a manutenção por 30, 60 e 90 dias à -20ºC. A viabilidade foi avaliada pelo método tradicional de cultura e a produção de transcritos, pela técnica de RT-PCR. A quantificação só foi possível no primeiro dia de análise (dia 0) e apresentou uma média de 3,0 x 107 UFC, e nos demais períodos de armazenamento as cepas apresentaram crescimento confluente, não permitindo sua enumeração. Os resultados indicaram que o leite integral UHT foi mais adequado para criopreservação em relação ao uso de neopeptona + 12% glicerol. A utilização de pré-tratamentos combinados com o uso de leite UHT como meio crioprotetor estabilizou as células para transcrever os genes ciaB, dnaJ, sodB e p19 nas cepas mantidas abaixo de -20° por 30 a 60 dias, indicando que são métodos mais adequados para a manutenção de cepas em laboratório.

Maintenance of strains of Campylobacter jejuni in laboratories after use of cryoprotectors and pre-treatment of stress / Manutenção de cepas de Campylobacter jejuni em laboratório após uso de crioprotetores e pré-tratamento de estresse

This study evaluated the feasibility and the production of transcripts of sodB, p19, ciaB and dnaJ genes in strains of Campylobacter jejuni ATCC 33291, NCTC 11351, and 2383 IAL stored in whole UHT milk and or neopepton + 12% glycerol, submitted or not to pre-treatments at 4°C or 10°C for 30 minutes. The analyzes were performed immediately after freezing in liquid nitrogen (day 0) and after maintenance for 30, 60, and 90 days at -20ºC. The viability was evaluated by the traditional culture method and the production of transcripts by the RT-PCR technique. The quantification was only possible on the first day of analysis (day 0) and presented a mean of 3.0 x 107 CFU, and in the other periods of storage the strains presented confluent growth, not allowing their enumeration. The results indicated that whole UHT milk was more adequate for cryopreservation than the use of neopepton + 12% glycerol. The use of pre-treatments combined with the use of UHT milk as a cryoprotective medium stabilized the cells in order to transcribe the ciaB, dnaJ, sodBand p19 genes in the strains maintained under -20 ° for 30 to 60 days, indicating that they are more suitable methods for the maintenance of strains in the laboratory.(AU)

Este estudo avaliou a viabilidade e a produção de transcritos dos genes sodB, p19, ciaB e dnaJ em cepas de Campylobacter jejuni ATCC 33291, NCTC 11351 e 2383 IAL armazenadas em leite integral UHT e / ou neopeptona + 12% glicerol, submetidas ou não a pré-tratamentos a 4°C ou 10°C durante 30 minutos. As análises foram realizadas imediatamente após o congelamento em nitrogênio líquido (dia 0) e após a manutenção por 30, 60 e 90 dias à -20ºC. A viabilidade foi avaliada pelo método tradicional de cultura e a produção de transcritos, pela técnica de RT-PCR. A quantificação só foi possível no primeiro dia de análise (dia 0) e apresentou uma média de 3,0 x 107 UFC, e nos demais períodos de armazenamento as cepas apresentaram crescimento confluente, não permitindo sua enumeração. Os resultados indicaram que o leite integral UHT foi mais adequado para criopreservação em relação ao uso de neopeptona + 12% glicerol. A utilização de pré-tratamentos combinados com o uso de leite UHT como meio crioprotetor estabilizou as células para transcrever os genes ciaB, dnaJ, sodB e p19 nas cepas mantidas abaixo de -20° por 30 a 60 dias, indicando que são métodos mais adequados para a manutenção de cepas em laboratório.(AU)

Enhanced production of prodigiosin by Serratia marcescens MO-1 using ram horn peptone

This work addresses the production of prodigiosin from ram horn peptone (RHP) using MO-1, a local isolate in submerged culture. First, a novel gram-negative and rod-shaped bacterial strain, MO-1, was isolated from the body of the grasshopper (Poecilemon tauricola Ramme 1951), which was collected from pesticide-contaminated fields. Sequence analysis of 16S rDNA classified the microbe as Serratia marcescens. The substrate utilization potential (BIOLOG) and fatty acid methyl ester profile (FAME) of S. marcescens were also determined. The effect of RHP on the production of prodigiosin by S. marcescens MO-1 was investigated, and the results showed that RHP supplementation promoted the growth of MO-1 and increased the production of prodigiosin. A concentration of 0.4% (w/v) RHP resulted in the greatest yield of prodigiosin (277.74 mg/L) after 48 h when mannitol was used as the sole source of carbon. The pigment yield was also influenced by the types of carbon sources and peptones. As a result, RHP was demonstrated to be a suitable substrate for prodigiosin production. These results revealed that prodigiosin could be produced efficiently by S. marcescens using RHP.(AU)