RESUMO
In the present study, a bacterium isolated from Marcha- a herbal cake used as traditional starter culture to ferment local wine in North East India, was evaluated for bacteriocin like inhibitory substance production and was tested against six food borne/spoilage causing pathogens viz. Listeria monocytogenes MTCC 839, Bacillus subtilis MTCC 121, Clostridium perfringens MTCC 450, Staphylococcus aureus, Lactobacillus plantarum and Leuconostoc mesenteroides MTCC 107 by using bit/disc method followed by well diffusion method. The bacterial isolate was identified as Brevibacillus borstelensis on the basis of phenotypic, biochemical and molecular characteristics using 16Sr RNA gene technique. Bacteriocin like inhibitory substance produced by Brevibacillus borstelensis AG1 was purified by gel exclusion chromatography. The molecular mass of the Brevibacillus borstelensis AG1 was found to be 12 kDa. Purified bacteriocin like inhibitory substance of Brevibacillus borstelensis was further characterized by studying the effect of temperature, pH, proteolytic enzyme and stability. Bacteriocin like inhibitory substance was found to be thermostable upto 100 °C, active at neutral pH, sensitive to trypsin, and partially stable till third week of storage thus showing a bright prospective to be used as a potential food biopreservative.
Assuntos
Bacteriocinas/isolamento & purificação , Bacteriocinas/farmacologia , Brevibacillus/isolamento & purificação , Brevibacillus/metabolismo , Bactérias Gram-Positivas/efeitos dos fármacos , Bacteriocinas/química , Cromatografia em Gel , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Microbiologia de Alimentos , Índia , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Peso Molecular , Filogenia , Estabilidade Proteica/efeitos da radiação , /genética , Análise de Sequência de DNA , TemperaturaRESUMO
Background: Cystoisospora (Isospora) belli is a coccidian, protozoan parasite that resides in the gastrointestinal tract of humans. It is mainly reported from HIV-positive individuals. However, a few cases have been reported in other immunosuppressed individuals including renal transplant patients, and those with lymphoma and leukemia. Materials and Methods: During a period of 5 years (2008-2012), approximately 1700 stool samples of immunosuppressed patients were screened for the presence of opportunistic parasitic infections by a modifi ed acid fast staining technique. Results: A total of 41 C. belli were reported, out of which 30 were HIV-positive individuals while 11 were HIV negative. The latter individuals were also immunosuppressed due to prolonged use of steroids or other immunosuppressive drugs. Twenty-six out of 30 HIVpositive patients and all the HIV-negative individuals with C. belli infection had diarrhea. Conclusion: All immunosuppressed individuals should be examined for the presence of opportunistic coccidian parasitic infections and treated accordingly and alternatively, isolation of opportunistic parasites should trigger a hunt for immunocompromised state to reduce the morbidity and mortality in such patients.
RESUMO
Bacteriocin, an antimicrobial agent having potential for food biopreservation was purified from Lactobacillus brevis (a safe food-grade bacteria isolated from Vari Kandal, a traditional fermented food of Himachal Pradesh by adopting a novel repeated washing method. Its purity was confirmed by SDS-PAGE and Native-PAGE. The relative molecular mass of bacteriocin was 93.74 kD, while specific activity and recovery were 35.52 folds and 17.13%, respectively. It showed high thermal stability and was active over wide range of pH and exhibited sensitivity to trypsin.