Fermented wheat extract contains a complex mixture of phenolics. Further study is necessary to identify the unknown phenolic compounds. The authors gratefully acknowledge the University Grant Commission, Govt. of India, New Delhi (No. F. 15-83/2011(SA-II))for financial assistance. “
“Methanotrophic bacteria utilize CH4 as their sole carbon and
energy source, and thus are important in the global carbon cycle [25]. They are highly diverse and found in a wide range of environments [9] and [25]. Most of the known methanotrophic bacteria belong to the Alphaproteobacteria and Gammaproteobacteria, and some Verrucomicrobia isolates are known to be methanotrophs [25]. They transform CH4 to CO2, with methanol, formaldehyde and formate as intermediates [9]. In the field of biotechnology, methanotrophs are Natural Product Library a valuable biological resource SD-208 ic50 because they can degrade the greenhouse gas methane, and co-metabolize various organic compounds [25] and [27]. Therefore, methanotrophs are used in environmental engineering systems to mitigate methane emission and to remove recalcitrant contaminants (e.g., trichloroethylene) [7], [20] and [23]. Various abiotic and biotic factors can affect the growth and activity of methanotrophs [1], [26] and [30]. Previous studies largely focused on abiotic factors such as oxygen, nutrients, moisture, and temperature, etc. to enhance methanotrophic activity [9] and [25]. However,
recent studies have indicated that methanotrophs interact significantly with other bacteria in different ways. Stable Morin Hydrate isotope probing (SIP) revealed metabolic interaction between methanotrophs and non-methanotrophic bacteria in a natural environment [12]. Iguchi et al. [13] recently found that isolates of Rhizobium, Sinorhizobium, Mesorhizobium, Xanthobacter, and Flavobacterium enhanced the methanotrophic activity of Methylovulum miyakonense (belonging to Gammaproteobacteria), and that the Rhizobium isolate stimulated the methanotrophic activities of other
Gammaproteobacteria methanotrophs belonging to Methylococcaceae, Methylomonas, and Methylobacter by producing an extracellular compound. Similarly, Stock etal. [26] reported that several heterotrophic bacterial isolates increased the biomass of co-cultures with methanotrophs. In addition, Ho et al. [10] reported that richness of heterotrophic bacteria was an important factor in stimulating methanotrophic activity. Microorganisms other than those isolates may also be able to enhance growth and/or activity of methanotrophs. These non-methanotrophic organisms could potentially be used as biological stimulators in methanotrophic engineering systems. To enhance methanotrophic systems using a biological stimulator, the interaction of the stimulator with methanotrophs should be elucidated. For instance, it should be determined if this type of biological stimulation is a density-dependent process.