Effects of growth substrate and partial removal of nucleic acids in the production of bacterial protein meal on amino acid profile and digestibility in mink

Abstract

Effects of growth substrate and nucleic acid reduction in the production of bacterial protein meal (BPM) were studied using a bacteria culture containing mainly Methylococcus capsulatus (Bath). BPM were produced on natural gas (>90% methane) (BPMG), methanol (BPMM), or methanol followed by nucleic acid reduction (BPMM-NAR). BPMG and BPMM had similar crude protein (CP) and amino acid contents, whereas BPMM-NAR had slightly higher CP and amino acid contents. Digestibility of CP and amino acids in mink was higher for BPMM than for BPMG. Tryptophan revealed the greatest difference in true digestibility (70.5% for BPMG vs 89.5% for BPMM) and lysine the least difference (93.2% for BPMG and 95.7% for BPMM). There were no differences in CP or amino acid digestibility between BPMM and BPMM-NAR. It was concluded that BPM grown on methanol gave higher digestibility of CP and amino acids than natural gas, probably due to lower proportion of bacterial intracellular membrane protein.

Prevention of soya-induced enteritis in Atlantic salmon (Salmo salar) by bacteria grown on natural gas is dose dependent and related to epithelial MHC II reactivity and CD8α+ intraepithelial lymphocytes

“…The slightly reduced crude protein digestibility with increasing BM inclusion is similar to previous results for salmonids ( 6 , 17 , 40 ) . This effect is likely to be caused by cell-wall components in BM, as seen with yeast products fed to salmonids ( 41 ) , and by the extensive intracytoplasmic membranes in M. capsulatus grown on natural gas, as suggested by Skrede et al ( 42 ) .…”

Purple bacteria screening for photoautohydrogenotrophic food production: Are new H2-fed isolates faster and nutritionally better than photoheterotrophically obtained reference species?

“…As target organisms, humans, pigs and penaeid shrimp were chosen and respectively meat (beef) [32,33], soybean meal and fishmeal [34,35] were used as conventional and comparative protein sources. The digestibility of the bacterial product was assumed to be 87.0 % [36]. The quality of the protein is classified according to the EAAI as superior (>1), high (0.95-1), good (0.86-0.95), useful (0.75-0.86) or inadequate (<0.75) [37].…”

Microbial conversion of waste gases into single-cell protein

“…27 However, nucleic acids can be removed during food processing, for example by nuclease treatment. 28 Another important aspect to consider in SCP production is from an economic point of view regarding feedstock availability, scalability and processing. Therefore, further advancements are important for producing cost-effective SCP.…”