Application of Antimicrobial Bacillus subtilis Strain as a Starter Culture to Improve Qualities and Safety of Fermented Soybean (SIENG) Produced in Cambodia

Fermented foods play a very important role in Cambodian health and nutrition,as well as other developing countries where food preservation methods may be limited.SIENG,a Khmer fermented soybean product,naturally contains both beneficial and pathogenic microorganisms.Traditional fermentation that relies on natural microbial flora and environmental conditions results in variable product quality and can lead to spoilage.A starter culture such as Bacillus subtilis can ensure the safety and stability of the products.The objective of this study is to control the growth of Gram positive pathogens contaminated into traditional fermented soybean(SEING)by using antimicrobial Bacillus subtilis isolated from the same kind of food.Out of 120 SIENG samples,49 B.cereus strains were isolated,and 12 of B.cereus were positively synthesized compared with the lyophilized control enterotoxin.Two of these strains(BTM8-7 and BTM8-8)produced high levels of enterotoxin.We identified five Bacillus strains with the ability to fight against indicator pathogenic microorganisms.Among the five strains,B.CeM6-2 had the highest activity level against Lactobacillus plantrum ATCC 8014 and the largest diameter.B.CeM6-2 tolerated up to 20 h at 30℃ and 22 h at 37℃.In testing the strains with PK and PK-PMSF enzymes,bacteriocin produced by the strain B.CeM6PK untreated and B.CeM6-2PK-PMSF had a significantly stronger ability to suppress all the pathogenic indicators from 0 h to 47 h compared to the B.CeM6-2PK.Moreover,CeM6-2 outperformed the Miyagino strains,as it actively produced bacteriocin that fought against all four indicator strains of Gram positive and lactic acid groups,especially against Listeria monocytogenes,Streptococcus pyrogene,Leuconostoc mesenterids and L.plantarum,from 0 h-58 h and 0 h-40 h at 35℃.CeM6-2(1%)strain had the highest ability to fight against B.cereus at 24 h and at 34 h to 44 h incubation as well.CeM6-2(10:0 mL)and CeM6-2(9:1 mL)have the strongest ability to fight against B.cereus at room temperature(48 h and 72 h).The longer incubation and time at room temperature produce the highest level of bacteriocin.Thus,bacteriocins produced by B.CeM6-2 can be used as a preservative in food processing industries to avoid food spoilage even in higher temperatures and time.

Ambient Air Pollution and Pulmonary Tuberculosis in Malaysia

Introduction: The possible impact of ambient air pollution exposure on the development of active tuberculosis (TB) remains obscure. This study investigated the potential role of ambient air pollution in activating pulmonary TB (PTB) compared to extrapulmonary TB (EPTB). Materials and Methods: Data on TB cases were obtained from national surveillance data in Malaysia during 2013 and air pollution data were obtained from 52 air-monitoring stations around the country for the 3-year period of 2011-2013. Analyses were performed to estimate the odds of PTB vs. EPTB with changes in the 3-year (2011-2013) average Air Pollutant Index (API) and specific ambient air pollutants. Results: Results showed that the 95th-percentile of API levels during 2011-2013 was moderate and it was not associated with PTB. However, the odds of active PTB compared to EPTB was significantly elevated with the 95th-percentile levels for particulate matter with an aerodynamic diameter of 10 μm or less (aOR = 1.006, 95% CI: 1.002, 1.011), p-value Conclusions: These results provide suggestive evidence of the effects of ambient air pollution on development of active pulmonary TB compared to extrapulmonary TB. Additional research on the impacts of ambient air pollution on TB is warranted.

Isolation, Characterization and Bio-Control Activities of Bacillus Subtilis from the Fermented Soybean in Cambodia

The objective of this study was to isolate Bacillus subtilis produced Bacteriocin from Khmer traditional fermented soybean to control the growth of pathogenic bacteria from 120 SIENG samples from 9 different local open markets in Phnom Penh, 1 local open market and 2 local producers in Kandal province in Cambodia. 119 out of 120 samples were positive with Bacillus subtilis strains. Fifteen of these isolated strains exhibited antimicrobial activity to Lactobacillus plantarum by agar well diffusion assay and one of them （CeM6-7 strain） exhibited strongest antimicrobial activity. The filtered supernatant of this strain also suppressed the growth of several Gram-positive pathogens （such as Staphylococcus aureus） or lactic acid bacteria in broth. The filtrate could also suppress the growth of L. plantarum inoculated into soymilk. Antimicrobial B. subtilis strain CeM6-7 is thought to be applicable for making a starter culture to produce much safe fermented soybean foods by suppressing the growth of naturally contaminated B. cereus or S. aureus during production. In addition, the use of this starter culture may contribute to prevent spoilage or quality loss of soybean products caused by the over growth lactic acid bacteria or other Gram-positive bacteria.

Optimization of carotenoids extraction from Penaeus semisulcatus shrimp wastes

Objective:To find effective method for carotenoids extraction from shrimp waste which is one of the important sources of natural carotenoids and produced in large quantities in Iran.Methods:Two methods of carotenoids extraction,enzymatic and alkaline(NaOH 1 normal)treatment,were assayed.About 5 g of gritted shrimp wastes were used at each stage.For alkaline treatment,sodium hydroxide were added to shrimp waste.After 48 h,the mixture was filtered and centrifuged.Results:Alcalase extraction produced(234.00±2.00)mg/L carotenoid and NaOH extraction produced(170.00±1.53)mg/L carotenoid.Based on the samples analyzed,alcalase enzyme showed more efficiency than NaOH extraction to achieve carotenoids from shrimp waste.Conclusions:It can be concluded that using alcalase enzyme for carotenoids extraction can produce higher carotenoids concentration than NaOH extraction method.So alcalase enzyme method can be used for achieving this kind of antioxidant.