Microbiology Research

550 KiB

Open AccessArticle

Effect of Low Power Microwave Radiation on Pigment Production in Bacteria

by Shreya Raval, Vimla Chaudhari, Haren Gosai and Vijay Kothari

Microbiol. Res. 2014, 5(1), 5511; https://doi.org/10.4081/mr.2014.5511 - 18 Dec 2014

Cited by 3 | Viewed by 474

Effect of low power (90 W) microwave (MW) radiation (2450 MHz) on bacterial growth and pigment production was studied in three different bacteria. Microwave exposure of 2–6 min duration was able to alter growth and pigment production (prodigiosin production by Serratia marcescens, [...] Read more.

Effect of low power (90 W) microwave (MW) radiation (2450 MHz) on bacterial growth and pigment production was studied in three different bacteria. Microwave exposure of 2–6 min duration was able to alter growth and pigment production (prodigiosin production by Serratia marcescens, violacein production by Chormobacterium violaceum, and staphyloxanthin production by Staphylococcus aureus) in the test organisms significantly. In this study, pigment production was estimated in the cell population originated from microwave treated inoculum, and not directly in the MW treated cells. Thus the alterations in pigment production and/or secretion might have been transferred from the originally MW treated cells to their daughter cells (who did not receive direct MW exposure), indicating the mutagenic influence of microwave radiation. Heavy prodigiosin overproduction observed in one of the test tubes inoculated with microwave treated S. marcescens could not be sustained by daughter populations corresponding to that tube, indicating the reversible nature of microwave induced mutation(s). The microwave effects observed in this study largely seem to be of athermal nature, as the thermal effect was minimized by use of ice during the microwave treatment. Full article

734 KiB

Open AccessArticle

Evaluation of Polymerase Chain Reaction Assay for Pathogenic Leptospira Detection in Stored Urine

by Carlos A. Rossetti and Victoria Boggia

Microbiol. Res. 2014, 5(1), 5427; https://doi.org/10.4081/mr.2014.5427 - 18 Dec 2014

Viewed by 349

Abstract

Pathogenic Leptospira spp. is the etiological agent of leptospirosis, a worldwide zoonotic infectious disease that causes jaundice, hemorrhages, renal failure and abortion in susceptible species. Urine is one of the preferred clinical samples for the detection of the agent. However due to its [...] Read more.

Pathogenic Leptospira spp. is the etiological agent of leptospirosis, a worldwide zoonotic infectious disease that causes jaundice, hemorrhages, renal failure and abortion in susceptible species. Urine is one of the preferred clinical samples for the detection of the agent. However due to its reliability, detection of leptospires in stored samples is challenged. Here we evaluated the capability of a polymerase chain reaction (PCR) assay for detecting pathogenic leptospira DNA in a non-sterile collected urine, stored at different times and temperatures. Our results indicate that the PCR protocol used detect pathogenic leptospira DNA but not non-pathogenic serovars or other non-leptospiral microorganisms. The sensitivity of the assay was of 100 Leptospira interrogans in 10 mL refrigerated neutralized urine within 72 h post collection. This protocol could be of considerable interest for public health workers, field veterinarians and laboratory scientists, in sampling and processing urine for the detection of pathogenic Leptospira spp. Full article

895 KiB

Open AccessArticle

Standardization of Lyophilization Medium for Streptococcus thermophilus Subjected to Viability Escalation on Freeze Drying

by Rohit Sharma, Bhagwan S. Sanodiya, Gulab S. Thakur, Pallavi Jaiswal, Anjana Sharma and Prakash S. Bisen

Microbiol. Res. 2014, 5(1), 5402; https://doi.org/10.4081/mr.2014.5402 - 2 Sep 2014

Cited by 9 | Viewed by 968

Abstract

The objective of the present study is to develop a lyophilization medium for Streptococcus thermophilus (NCIM 2904) as the industrial exploitation of this bacterium totally depends upon preservation and lyophilization protocols. Protective effect of 18 compounds were observed individually and in combinations with [...] Read more.

The objective of the present study is to develop a lyophilization medium for Streptococcus thermophilus (NCIM 2904) as the industrial exploitation of this bacterium totally depends upon preservation and lyophilization protocols. Protective effect of 18 compounds were observed individually and in combinations with different sugars, sugar alcohols, polymers, protein concentrates and buffers. Among all the protectants tested, ammonium citrate (1% w/w), K₂HPO₄ (1% w/w) and KH₂PO₄ (1% w/w) provided lowest protection to these bacterial cells while 10% (w/w) sodium caseinate, whey protein concentrate, sweet whey powder, and skim milk showed significant results in viability escalation. Survival in carbon sources like lactose, sucrose and maltodextrine was also favored maximally. Combination of sodium caseinate 10%, skim milk 5%, sucrose 5%, lactose 5% and mono sodium glutamate 1% in distilled water in ratio of 1:5 with S. thermophilus showed survival percentage of 96%. Full article

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Microbiol. Res., Volume 5, Issue 1 (September 2014) – 3 articles

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