Insects such as the black soldier fly (BSF; Hermetia illucens) are currently being promoted as an alternative protein source for animals and organic waste management agents. To play the dual roles sustainably, there is need to reduce reliance on wild BSF and develop an appropriate farming methodology for the insect. This study aimed at improving larvae production in a black soldier fly colony previously established from the wild in Kenya. The study explored the effect of four locally available organic wastes as feedstocks for production the black soldier fly larvae. Separate feeding trials on faecal sludge (FS), banana peelings (BP), brewer’s waste (BW) and restaurant food waste (FR) was done and their effect on BSF larvae growth rate, larvae weight, total prepupal yield in grams, crude protein and lipid (ether extract) content analysed. The efficiency of the BSF larvae to consume and therefore reduce the waste load of the different substrates was also evaluated. Results showed that BSF larvae fed on FR had significantly higher (P<0.05) total mean yield and average individual weight of 196.9±4.0 g and 0.101±0.002 g, respectively, followed by BW (154.8±6.5 g, 0.078±0.02 g), FS (138.7±5.0 g, 0.070±0.001 g) and with BP the lowest (108.9±5.6 g, 0.055±0.002 g). The harvested BSF larvae crude protein was significantly higher for FS and BW at 45.4±0.1% and 43.0±1.0%, respectively. However, ether extract content was variable and dependent on feedstock used with lower values reported for FS and BW (18.1±0.3% and 27.2%, respectively), and highest for food remains prepupa (36%). Dry matter reduction ranged between 50.3-81.8% with corresponding bioconversion and feed conversion rates ranging from 14.9-20.8% and 2.6-4.5, respectively, was achieved for the substrates used. These results indicated the potential of utilising BSF composting in valorisation of the local organic wastes for their bioremediation from the environment. Due to their availability in large quantities and their low cost, these organic wastes can form important feedstock resources for the sustainable production of BSF larvae as a future alternative protein source for both animal feeds at farm level and industrial scale. In conclusion, embracing nutrient recycling through BSF technology by resource-constrained farmers in Kenya will contribute to food security through supply of proteins for production of poultry and fish.

The utilisation of insect as ingredients for animal feeds has gained considerable interest recently. For example, the potential of black soldier fly (Hermetia illucens; BSF) larvae as a cheap alternative protein source for animal feeds seems to show promising perspectives, especially for poultry and aquaculture feeds. In the present study, we sought to establish the wild availability of BSF in Bondo area of Western Kenya, and to develop appropriate methods for larvae farming for utilisation in smallholder farming systems using organic waste substrates. Using an open system involving a larvae feeding structure, study results showed that BSF is native to the study area with higher production observed on substrates of plant origin compared to those of animal origin. Proximate, mineral and vitamin analysis showed that wild BSF larvae contained: 40% crude protein, 33% crude fat, 15% ash, 12% crude fibre, 0.56% manganese, 3.07% sodium, 0.57% iron, 2.27% potassium, 0.24 mg/100 g thiamin, 2.2 mg/100 g riboflavin and 1.3 mg/100 g vitamin E. This nutritional profile of the wild BSF larvae indicates its potential to serve as a cheap and sustainable substitute protein source. We therefore recommend small-scale poultry and fish farmers to adopt the identified methods for its cultivation as a way of lowering production costs and also contributing to environmental hygiene and sanitation.

The dual roles of efficient degradation and bioconversion of a wide range of organic wastes into valuable animal protein and organic fertiliser, has led to increased interest in black soldier fly (BSF) technology as a highly promising tool for sustainable waste management and alternative protein production. The current study investigated the potential application of BSF technology in the valorisation of faecal sludge (FS), a common organic waste in the urban informal settlements in low and middle-income countries. We evaluated the effect of different feeding rates (100, 150, 200 and 250 mg/larva/day), different feeding regimen and supplementation with other waste feedstock (food remains, FR; brewers waste, BW; and banana peelings, BP) on BSF larvae (BSFL) growth rates/yield and FS reduction efficiency. Results showed significantly (P<0.01) higher prepupal yield (179±3.3 and 190±1.2 g) and shorter larval development time (16.7 and 15 days) when reared on 200 and 250 mg/larva/day FS, respectively. However, different feeding regimes of FS did not significantly affect larval growth rate and prepupal yield (P=0.56). Supplementation of FS with other organic substrates resulted in significantly increased BSFL biomass production and substrate reduction, and shortened larval development time; with the effect was more pronounced when FS was supplemented with FR and at 30% supplementation. Protein:fat ratios for BSFL reared on FS, FS:FR, FS:BW were significantly (P<0.05) higher (2.51, 2.53, and 2.44, respectively) compared to FS:BP mixture (1.99). These results demonstrated that supplementation of FS with locally available organic waste can be used to improve its suitability as feedstock for BSF production and organic waste bioremediation from the environment. In conclusion, a daily feeding strategy of substrate containing FS supplemented with 30% organic waste co-substrate at feeding rate of 200 mg/larva/day can be used as a guideline for BSFL mass production and bioremediation of FS both at small- and large-scale level.

Microbes inhabitants of extreme environments such as soda lakes are useful in biotechnology as sources of novel enzymes and metabolites, which can survive and function in the harsh conditions of the industrial processes. A number of such extremophiles have been isolated and described from Kenyan lakes. The present study isolated a total of 37 isolates from Lake Magadi, a hypersaline (up to 30% salinity) and alkaline lake (12.5 pH levels), using mineral rich and carbon rich media types. They were characterized and screened for the ability to produce useful biotechnological enzymes and biomolecules by cultural, biochemical and molecular approaches. 34 of the isolates were Gram positive; one was Gram negative and two were Gram variable. Most of the isolates grew well at pH ranging from 6.0-11.0, (optimum 9.0-10.0), temperature range of 20-45 o C (optimum of 30-35 o C) and salinity range of 5-30%, optimum growth was noted at 10-15%. 15 isolates produced various extracellular enzymes such as amylases, lipases and proteases. Blast analysis of their partial sequences showed that the bacteria belonged to genera Bacillus, Clostridium and Halomonas, with relative abundances of 54%, 38% and 8% respectively. The similarity values of some of the isolates to their closest neighbours (78% 80%, 84%, 85%, 88% and 94-97%) show that they may represent new species or novel genera respectively within the lake ecosystem. The study results are discussed in terms of their ecological importance to the lake system and potential biotechnological application.

Background Edible insects are a sustainable source of high-quality animal protein. Insect farming is gaining interest globally, particularly in low-income countries, where it may provide substantial nutritional and economic benefits. To enhance insect farming practices in Africa, new farming systems are being developed. However, knowledge on how to best promote uptake of these systems is lacking. This study aims to fill this gap by investigating the effectiveness of educational interventions in promoting insect farming for household consumption in Africa. Method The study is designed as a multi-site randomized controlled trial to evaluate the impacts of agricultural training alone or in combination with nutrition education on the adoption of insect farming in Ghana, Kenya and Uganda. In each of the three countries, ninety-nine villages are randomly assigned to one of three arms: two intervention arms and a control arm with no interventions. Focusing on production (P), the first intervention arm covers agricultural training on insect farming combined with provision of insect production starter kits. Focusing on both production and consumption (PC), the second intervention arm involves the same intervention components as treatment P plus additional nutrition education. The impacts of the interventions are measured by comparing baseline and endline data collected one year apart. Primary outcomes are adoption of insect farming and consumption of the farmed insects. Discussion Understanding the drivers and impacts of novel agricultural practices is crucial for transitioning to sustainable food systems. The current project is the first to investigate how educational interventions promote insect farming for household consumption in low-income countries. The results will contribute evidence-based knowledge to support sustainable development through insect farming in Africa. Trial registration The protocol is registered in the American Economic Association registry for randomized control trials with registration number AEARCTR-0009996. Initial registration date: 02 September 2022, last updated 17 May 2023.