ENHANCED PRODUCTION OF SINGLE CELL PROTEIN FROM M. capsulatus (BATH) GROWING IN MIXED CULTURE

Abstract

The growing global demand for nutritional protein means that a sustainable source such as Single Cell Protein from Methylococcus capsulatus (Bath) can become a potential replacement for fishmeal and other animal feeds. Improving biomass concentrations using statistical optimization during synergistic fermentations with a mixed consortium of the three heterotrophic bacteria Alcaligenes acidovorans, Aneurinibacillus danicus, and Brevibacillus sp. can increase the feasibility of the industrial process. The medium components Mg2+, Ca2+, Fe3+, Cu2+, PO42-, NO3-, MoO42-, trace metals, and process temperature were screened using a two-level Plackett-Burman Design in shake flasks which resulted in Cu2+ being the only significant factor. The optimum level of CuSO4.5H2O was found to be 40 μM using One Factor Response Surface Methodology, which was three times higher than the typical values of Cu2+ used previously. These combined strategies led to a 265% increase in biomass, with final cell concentration of 10.3 g/L, up from 2.8 g/L in fed batch fermentations over 48 hours. The heterotrophic bacteria did not grow on NMS or methane but increased biomass concentration when added to M. capsulatus (Bath) cultures.

A Genome-Scale Metabolic Model for Methylococcus capsulatus (Bath) Suggests Reduced Efficiency Electron Transfer to the Particulate Methane Monooxygenase

“…Specifically the latter studies have been triggered by a considerable commercial interest in M. capsulatus (Bath) as the primary microbe used for the production of Single Cell Protein (SCP) as animal feed starting in the 70 s (Øverland et al, 2010). Now that hydraulic fracturing has made natural gas a cheap and abundant feedstock (Ritala et al, 2017), the application of M. capsulatus (Bath) for this purpose is being explored again (Nunes et al, 2016; Petersen et al, 2017). Another portion of studies, however, has focused on uncovering the biochemical and genetic basis of the organism’s unique metabolism (Anthony, 1983).…”

Cultivation of methanotrophic bacteria in a novel bubble-free membrane bioreactor for microbial protein production

“…Several reports have described the ability of methanotrophs to produce a wide range of metabolites that can sustain the growth of very diverse heterotrophic bacteria (Bothe et al, 2002;Karwautz et al, 2018;Oshkin et al, 2015;Stock et al, 2013;van der Ha et al, 2013). Thus, many feed formulae based on methanotrophic bacteria include also heterotrophs (Bothe et al, 2002;Nunes et al, 2016). Heterotrophs co-cultivated with methanotrophs support the culture stability, as they are able to remove some metabolites that could potentially inhibit MOB growth (e.g., acetate or formate) (Bothe et al, 2002;van der Ha et al, 2013).…”

“…Oxygen supply Methane supply [37][38][39][40][41][42][43][44][45][46][47] Atmospheric air -16.89 ml h -1 15.78 ml h -1 47-73 Atmospheric air -29.01 ml h…”

Bioconversion of wastewater to single cell protein by methanotrophic bacteria

“…A robust bacterial consortium can neglect the demand for strictly sterile conditions, which would reduce the operational costs (Tsapekos et al, 2019). Furthermore, the nutrients and feeding requirements for mixed cultures are also reduced accordingly (Nunes et al, 2016).…”