https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 Arsenic contamination in areas surrounding mines and selection of potential As-resistant purple nonsulfur bacteria for use in bioremediation based on their detoxification mechanisms https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29583  L28 > C1. Strains AB3, C31, and L28 accumulated higher levels of intracellular vitamin B12 than strain C1. However, only strain C1 produced SAM and showed As biovolatilization activity. When strain C1 was incubated under microaerobic light conditions, it produced arsenobetaine [(AsB(V)] in medium with As(III) and monomethylarsonic acid [MMA(V)] in medium with As(V), which were found in the culture supernatants. Volatile methylated As compounds, such as dimethylarsenic acid [DMA(V)] and MMA(V)], were also detected in strain C1 during 30 days of incubation with As(III) and As(V). Strains AB3, C1, and L28 were identified as Rhodopseudomonas palustris and strain C31 as Rubrivivax benzoatilyticus. The resistance of these strains to As [As(III) and As(V)] based on minimum inhibition concentration values under aerobic dark and microaerobic light conditions, respectively, was in the order of C1 > AB3 > C31 > L28. The overall results demonstrate that all four selected strains of PNSB have a great potential for future application in the remediation of As-contaminated areas although R. palustris C1 was the most effective candidate.]]> Tue 31 Jul 2018 16:28:15 AEST ]]> Dairy propionibacteria as direct-fed microbials: in vitro effect on acid metabolism of Streptococcus bovis and Megasphaera elsdenii https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47504 Megasphaera elsdenii and Streptococcus bovis in various co-culture combinations in a simulated rumen environment comprising unmodified rumen digesta supplemented with excess glucose. While suppression of lactic acid accumulation by both the dairy propionibacteria and M. elsdenii in the presence of S. bovis in the simulated rumen conditions was evident, propionibacteria were found to be more effective than M. elsdenii in controlling lactic acid levels.]]> Mon 23 Jan 2023 12:08:28 AEDT ]]>