The aquaculture industry with its rapid growth trajectory requires a stable supply of a protein source that is optimal and sustainable, ensuring growth, health and well-being of farmed animals. The stagnating production of fishmeal (FM), price volatility, environmental impact of reduction fisheries and growing scrutiny on the conversion of food grade fish to fish meal and fish oil and discussions over “fish-in fish-out ratios” are issues of concern.
String Bio’s microbial protein offers a good alternative to fishmeal and is manufactured in a sustainable way by leveraging the String Integrated Methane Platform (SIMP). SIMP is an IP protected technology that enables sustainable manufacturing of ingredients for everyday living from methane. Bacteria are advantageous due to their high growth rates and efficient conversion of substrates to proteins. Methanotrophic bacteria utilize methane as a carbon and energy source. The efficient energy utilization of the methanotrophic bacteria in the conversion of methane to protein reduces greenhouse gas emission concomitantly to a substantial amount.
String Bio’s microbial protein-based products were tested in various inclusions in the growth trials of pacific white shrimp1,2, Penaeus vannamei for 12-weeks, rainbow trout3, Oncorhynchus mykiss for 9-weeks and yellowtail kingfish4, Seriola lalandi for 35-days. In all these trials, there was significant increase in body weight gain of animals that were fed with String Bio’s microbial protein as a FM replacement. The digestibility of diets in these species was also better than the control diets. Histological observations of the gastrointestinal tract, liver and kidney did not show any differences between dietary treatments in rainbow trout. The relative gene expression of growth-related genes such as GHR, IGF-1 and IGF-2 in the SCP fed rainbow trout were higher than control fed fishes. Similarly, relative expression of the immune related genes such as lysozyme and toll-like receptor in the SCP fed animals was upregulated, when compared to control fed shrimps. These studies clearly validate String’s microbial protein as a sustainable, alternative protein ingredient for the various groups of species such as crustaceans, salmonids or marine finfish.
1Felix N et al., Evaluation of single cell protein on the growth performance, digestibility and immune gene expression of Pacific white shrimp, Penaeus vannamei.
2Nederlof M et al., (2021). Effect of different types of single cell protein on feed intake, growth, body composition and digestibility of whiteleg shrimp (Litopenaeus vannamei). Aquaculture Europe 2021 - Funchal, Madeira, Portugal.
3Rajesh M et al., (2022). Evaluation of a novel methanotroph bacteria meal grown on natural gas as fish meal substitute in rainbow trout, Oncorhynchus mykiss. Aquaculture Research, 53, 2159-2174. https://doi.org/10.1111/are.15735
4Pilmer L W et al., (2022). Using dietary additives to improve palatability of diets containing single-cell protein from methanotrophic bacteria in yellowtail kingfish (Seriola lalandi) diets. Aquaculture Research. https://doi.org/10.1111/are.15986