Bioconversion of Gibberellin Fermentation Residue into Feed Supplement and Organic Fertilizer Employing Housefly (Musca domestica L.) Assisted by Corynebacterium variabile

Abstract

The accumulation of a considerable quantity of gibberellin fermentation residue (GFR) during gibberellic acid A3 (GA3) production not only results in the waste of many resources, but also poses a potential hazard to the environment, indicating that the safe treatment of GFR has become an urgent issue for GA3 industry. The key to recycle GFR is converting it into an available resource and removing the GA3 residue. To this end, we established a co-bioconversion process in this study using house fly larvae (HFL) and microbes (Corynebacterium variabile) to convert GFR into insect biomass and organic fertilizer. About 85.5% GA3 in the GFR was removed under the following optimized solid-state fermentation conditions: 60% GFR, 40% rice straw powder, pH 8.5 and 6 days at 26°C. A total of 371g housefly larvae meal and 2,064g digested residue were bio-converted from 3,500g raw GFR mixture contaning1, 400g rice straw in the unit of (calculated) dry matter. HFL meal derived from GFR contained 56.4% protein, 21.6% fat, and several essential amino acids, suggesting that it is a potential alternative animal feed protein source. Additionally, the digested GFR could be utilized as an organic fertilizer with a content of 3.2% total nitrogen, 2.0% inorganic phosphorus, 1.3% potassium and 91.5% organic matter. This novel GFR bio-conversion method can mitigate potential environmental pollution and recycle the waste resources.

Insects as feed: house fly or black soldier fly?

“…In fact, they can fully develop on desiccated Escherichia coli (Levinson, 1960) and can utilise yeasts (Haupt and Busvine, 1968) and fungi (Pimentel et al, 2018). Hence, inoculating a substrate with bacteria, fungi or yeasts can enhance bioconversion (Brookes and Fraenkel, 1958;Qi et al, 2019;Yang et al, 2015). Conversely, the adaptation to feeding on microbiota might prohibit HF from ingesting and therefore digesting larger particles, especially compared to the larger BSF.…”

Characterization of Dark Septate Endophytic Fungi and Improve the Performance of Liquorice Under Organic Residue Treatment

“…(Chovanec et al, 2001). Moreover, plant–microbe–manure tripartite interactions may play vital roles in sustainable agricultural management under stressed condition because such associations play an important role in improving the performance of crops (Yang et al, 2015).…”

Insect left-over substrate as plant fertiliser

“…Increases in organic carbon were also observed in house fly treatments. Gibberellin fermentation residue digested by houseflies contained 1.3% potassium, 3.2% total nitrogen, 2.0% inorganic phosphorus, and 91.5% organic matter (Yang et al, 2015b). These concentrations are appropriate proportions to what is often required for crop productivity and further indicate housefly waste as a potential biofertiliser.…”

“…They are typically acknowledged as a nuisance to livestock farmers, but efforts have been made to demonstrate that their larvae could be useful as livestock feed as well. Houseflies reared on gibberellin fermentation produce similar protein and fat concentrations to meal worms and black soldier fly larvae (Yang et al, 2015b). Poultry waste bioconverted by housefly larvae have resulted in large reductions of moisture content (75 to 50%).…”