Bioconversion Rate Research Articles

Efficient and green preparation of baicalein from Radix scutellariae with deep eutectic solvent pretreated bioconversion of cellulose-based microreactor

To enhance the bioconversion ratio, an efficient and green bioconversion method for the preparation of baicalein with a microreactor composed of edible microorganisms (Aspergillus oryzae and Yeast) treated with deep eutectic solvent co-immobilized on magnetic cellulose was investigated. Various types of deep eutectic solvents (DES) were screened to obtain a superior biocatalytic effect. NADES (CHCL/EG) harvested the maximum catalytic effect at 1.0 wt% under optimal conditions (concentration of bacterium 1.5 × 107 (C × 107 cells/mL), wet weight of microreactor 12 g, incubation temperature 33 °C and pH 5.0, liquid-solid ratio 30:1 (mL/g), incubation time 48 h), baicalein reached 66.36 mg/g, which increased 3.46-fold to that of normal sample after optimizing. DES could increase the permeability of the cell membrane. The bioconversion rate of baicalin reached 97.2%.Moreover, IC50 values of the extracts measured by the DPPH-radical scavenging test were 0.366 mg/mL (control sample 0.674 mg/mL). The residual activity of the microreactor was 80.2 % after using it 14 times. The experimental results showed that bioconversion is an effective method for preparing baicalein from the plants.

Evaluating the Influence of Nutrient-Rich Substrates on the Growth and Waste Reduction Efficiency of Black Soldier Fly Larvae

Background: The black soldier fly (Hermetia illucens) has emerged as a promising tool in sustainable waste management, owing to its larvae’s ability to efficiently convert organic waste into valuable biomass. Objective: This study investigates the impact of various substrate compositions on the growth, waste reduction efficiency, and bioconversion rate of black soldier fly (BSF) larvae (Hermetia illucens). The aim is to optimize feeding strategies to enhance the effectiveness of BSF larvae in sustainable waste management and protein production. Methods: A controlled experiment was conducted over a 20-day period, using four different substrate types: 100% sludge, 75% sludge + 25% chicken feed, 25% sludge + 75% chicken feed, and 100% chicken feed. Each treatment had three replicates with 100 larvae each. Larval growth metrics, including weight and width, were recorded bi-daily. The waste reduction efficiency and bioconversion rate were calculated based on the remaining substrate weight and larval biomass, respectively. Elemental analysis was performed to determine the impact of substrate type on the accumulation of various elements in the larvae. Results: Significant differences were observed in larval growth, waste reduction efficiency, and bioconversion rates across the different substrates. The 100% chicken feed substrate led to the highest larval growth (M = 0.0881 g/day, SD = 0.0042) and bioconversion rate (M = 7.52%, SD = 0.34), while the 100% sludge substrate achieved the highest waste reduction rate (M = 86.2%, SD = 2.15). ANOVA tests indicated that substrate composition significantly affected these outcomes (p < 0.05). Elemental analysis showed substantial variations in the concentrations of calcium, cadmium, and nickel among the substrates, with the 100% sludge substrate having the highest nickel accumulation (M = 0.2763 ppm, SD = 0.023), significantly different from the other treatments (p < 0.001). Conclusions: The results demonstrate that substrate composition is crucial for optimizing BSF larvae growth and waste reduction efficiency. Nutrient-rich substrates, such as chicken feed, significantly enhance bioconversion rates and larval biomass production, although careful consideration of elemental accumulation, especially heavy metals, is essential for safe application in animal feed.

Black Soldier Fly (Hermetia illucens) Microbiome and Microbe Interactions: A Scoping Review.

Black soldier fly (Hermetia illucens, BSF) is farmed worldwide to convert organic waste into usable biomaterials. Studies on the larval microbiome have been carried out to check for symbiotic or pathogenic microbes and their respective functions and fates. Some studies tested these microbes for industrial applications, while others tested the effects of exogenous microbes as probiotics or for substrate pre-processing to improve larval fitness, bioconversion rates, or nutritional qualities. This review examined all peer-reviewed literature on these topics to consolidate many disparate findings together. It followed the PRISMA guidelines for scoping reviews. The results found no evidence of globally conserved core microbes, as diet strongly correlated with gut microbiome, but some genera appeared most frequently in BSF larval guts worldwide regardless of diet. The gut microbes undoubtably assist in digestion, including pathogen suppression, and so microbial probiotics show promise for future investigations. However, the common gut microbes have not been explored as probiotics themselves, which would be a promising direction for future work. The impacts of BSF bioconversion on pathogens varied, so each rearing facility should investigate and manage their pathogen risks independently. The data summarized in this study provide useful reference points for future investigations into BSF-microbe interactions.

Reusable Immobilized Lactobacillus futsaii CS3 for Enhanced GABA Synthesis using Low-Cost Substrates in Fermenter-Scale Batch and Fed-Batch Fermentations

On the industrial scale, the cost of commercial culture media for the production of gamma-aminobutyric acid (GABA) is a very important factor. This study employed a low-cost substrates and by-product from agri-food industry for GABA synthesis by Lact. futsaii CS3 at the fermenter-scale. Lact. futsaii CS3 cells were immobilized in 3 % (w/v) sodium alginate and employed for GABA synthesis in the optimal modified MRS medium (3.48 % (w/v) cane sugar, 3.84 % (w/v) tuna condensate waste and 10.77 % (w/v) monosodium glutamate (MSG)) with the initial pH medium of 5, fermentation temperature at 37 °C and agitation speed at 30 rpm. During the 60th h of batch fermentation without pH control, immobilized Lact. futsaii CS3 efficiently transformed MSG into the highest GABA of 19.05 g/L, achieving the volumetric productivity of 0.32 g/L/h with a bioconversion rate of 29.01 %. To further enhance GABA production, MSG (7.5 % w/v) was fed into the fermenter during the 48th h of fed-batch fermentation, aiming to amplify GABA synthesis. The maximum GABA (26.28 g/L) was synthesized at 84 h of fed-batch fermentation, and the volumetric productivity and a bioconversion rate of 0.31 g/L/h and 23.59 %, respectively, were obtained. Fed-batch fermentation significantly outperformed batch fermentation, resulting in a 37.95 % increase in GABA production. Moreover, immobilized Lact. futsaii CS3 cells could be reused in 2 batch cycles. In the 1st reusability, the maximum GABA synthesis reached 25.94 g/L, and the volumetric productivity and a bioconversion rate of 0.31 g/L/h and 23.29 %, respectively, were achieved at 84 h of fed-batch fermentation. While in the 2nd reusability, GABA synthesis decreased to 23.29 g/L, with the volumetric productivity and a bioconversion rate of 0.28 g/L/h and 20.91 %, respectively, at 84 h of fed-batch fermentation. HIGHLIGHTS GABA production utilizing agri-food industry by-product. GABA production was enhanced by cane sugar and tuna condensate waste. Immobilized futsaii CS3 produced GABA 19.05 g/L (batch). Immobilized futsaii CS3 produced GABA 26.28 g/L (fed-batch). Immobilized futsaii CS3 could be reused in 2 batch cycles on GABA production. GRAPHICAL ABSTRACT

Feed-shifting strategy for increasing biodiesel production from black soldier fly larvae

The aim of this study was to increase the bioconversion efficiency (lipid accumulation) of black soldier fly larvae while simultaneously increasing biodiesel production through a feed-shifting strategy. Feeding with low-lipid feed promoted an increase in larval weight, while high-lipid feed resulted in greater lipid accumulation. Based on this result, a feed-shifting strategy was introduced, which consisted of two stages: first, increasing larval body weight using low-lipid feed, followed by lipid induction for biodiesel production using high-lipid feed. The use of this strategy resulted in an increase in the dry weight of larvae by ≥16 % compared to single feeding systems. This led to a 20 % increase in biodiesel productivity. The waste reduction ratio was enhanced due to the higher bioconversion rate in the feed-shifting strategy compared to that in the single feeding systems. The feed-shifting strategy would contribute to the enhancement of waste-to-energy efficiency.

Utilization of Black Soldier Fly and Housefly as Biodegradation Agents of Dairy Wastes and source of Animal Feed

Accumulation of dairy wastes and shortage of nutritious feed remain the major challenges in dairy cattle production. Such wastes may sustainably be biodegraded by black soldier fly (BSF) larvae and housefly (HF) larvae into their which ca be used as animal feed. This study was done to compare the capacity of using black soldier fly larvae (BSFL) and housefly larvae (HFL) to manage dairy wastes and use of such larvae as livestock feed. Biomass reduction rate, biomass reduction index, bioconversion rate, feed conversion ratio and nutritional profile of resultant BSF and HF prepupae raised on cow dung (CD) and dairy shed effluent (DSE) were determined. In order to ascertain whether the substrates had an effect on BSFL and HFL, analysis of variance (ANOVA) was used, and multiple mean comparisons at P≤0.05 were done using the Tukey HSD post-hoc test. Housefly larvae reared on DSE had the highest biomass reduction rate and biomass reduction index, even though HFL had a shorter development time than BSFL (P≤0.05). Housefly prepupae reared on DSE had the highest crude protein content of 60.1 % of all the HF prepupae counterparts and BSF prepupae reared on DSE and CD (P≤0.05), Hence HF prepupae could be an alternative source of animal feed. Depending on the needs and purpose, utilization of fly larvae to manage dairy waste is viable and effective option

Co-treatment of agri-food waste streams using black soldier fly larvae (Hermetia illucens L.): A sustainable solution for rural waste management

The management of rural waste, particularly agri-food waste, poses a major challenge to the ecosystem health. This study investigated the efficacy of black soldier fly larvae (Hermetia illucens L., BSFL) bioconversion for agri-food waste under independent treatment or co-treatment strategies using chicken manure and food waste as a model system. The results showed a synergistic effect of co-treating agri-food waste from different sources. The co-treatment strategy enhanced bioconversion efficiency, resulting in a 1.31-fold waste reduction rate and a 1.93-fold bioconversion rate. Additionally, larval growth performance and biomass quality of BSFL were improved, while lauric acid and oleic acid were enriched in the larval fat from the co-treatment strategy. 16S rRNA amplicon sequencing revealed that the co-treatment strategy reshaped both the residue and larval gut microbiota, with distinct enrichment of taxonomical biomarkers. Furthermore, under this strategy, metabolic functions of the residue microbiota were significantly activated, especially carbohydrate, amino acid, and lipid metabolism were enhanced by 16.3%, 23.5%, and 20.2%, respectively. The early colonization of lactic acid bacteria (Weisella and Aerococcus) in the residue, coupled with a symbiotic relationship between Enterococcus in the larval gut and the host, likely promoted organic matter degradation and larval growth performance. Scaling up the findings to a national level in China suggests that the co-treatment strategy can increase waste reduction quantity by 86,329 tonnes annually and produce more larval protein and fat with a market value of approximately US$237 million. Therefore, co-treatment of agri-food waste streams using BSFL presents a sustainable solution for rural waste management that potentially contributes to the achievement of SDG2 (Zero Hunger), SDG3 (Good Health and Well-Being), and SDG12 (Responsible Consumption and Production).

Comparison of primary and secondary metabolites and antioxidant activities by solid-state fermentation of Apios americana Medikus with different fungi

This study compared the nutritional components, isoflavones, and antioxidant activities by solid-sate fermentation of Apios americana Medikus (AAM) with seven different fungi. The total fatty acid contents increased from 120.5 mg/100 g (unfermented AAM, UFAAM) to 242.0 to 3167.5 mg/100 g (fermented AAM, FAAM) with all fungi. In particular, the values of total fatty acids were highest (26.3-fold increase) in the FAAM with Monascus purpureus. The amount of total free amino acids increased from 591.69 mg/100 g (UFAAM) to 664.38 to 1603.07 mg/100 g after fermentation except for Monascus pilosus and Lentinula edodes. The total mineral contents increased evidently after fermentation with M. purpureus, F. velutipes, and Tricholoma matsutake (347.36 → 588.29, 576.59, and 453.32 mg/100 g, respectively). The UFAAM predominated isoflavone glycosides, whereas glycoside forms were converted into aglycone forms after fermentation by fungi. The bioconversion rates of glycoside to aglycone were excellent in the FAAM with M. pilosus, M. purpureus, F. velutipes, and T. matsutake (0.01 → 0.69, 0.50, 0.27, and 0.31 mg/g, respectively). Furthermore, the total phenolic contents, total flavonoid contents, and antioxidant activities by the abovementioned FAAM were high except for L.edodes. This FAAM can be used as a potential food and pharmaceutical materials.

Resource Utilization of Residual Organic Sludge Generated from Bioenergy Facilities Using Hermetia illucens Larvae.

Residual organic sludge generated from bioenergy facilities (BF-rOS) is often disposed instead of recycled, thus contributing to further environmental pollution. This study explored the resource utilization of BF-rOS using Hermetia illucens larvae (BSFL). When BF-rOS was fed to BSFL for two weeks, the dry weight per individual BSFL was approximately 15% of that of BSFL that were fed food waste (FW). However, the dry weight increased by approximately two-fold in BSFL that were fed effective microorganism (EM)-supplemented BF-rOS containing 60% moisture. However, under both conditions, the BSFL did not mature into pupae. In contrast, the highest dry weight per BSFL was observed with the BF-rOS/FW (50%:50%) mixture, regardless of EM supplementation. Furthermore, the highest bioconversion rate was observed when the BSFL were fed the BF-rOS/FW (50%:50%) mixture, and the frass produced by the BSFL contained fertilizer-appropriate components. In addition, the nutritional components of the BSFL exhibited a nutrient profile suitable for animal feed, except for those fed BF-rOS only. In conclusion, this investigation demonstrates that BF-rOS should be recycled for fertilizer production by mixing it with FW as a BSFL feed, which generates the valuable insect biomass as potential nutrition for animal feeding.

Bio-treatment of Cheese Whey by Black Soldier Fly Larvae (Hermetia illucens) reared in Algeria

Whey, a by-product of cheese industry, poses environmental challenges when discharged untreated. This study aimed to mitigate whey pollution and transform it into value-added products using black soldier fly larvae (BSFL). By investigating whey effects on BSFL growth and performance, an innovative waste management strategy was explored. The five-old-day larvae were fed with four diets; dry spent coffee ground (SCG) as the control diet, while SCG wetted with acid, sweet and fermented whey were the test diets. The results showed that whey types increased significantly (p < 0.05) BSFL growth compared to the control, the dry weight (53.83±0.49 Vs 25.10±0.18 mg/larva), growth rate (1.59±0.06 Vs 0.44±0.01 mg/day) and survival rate (78.83±1.25 Vs 68.50±1.5 %) of larvae and reduced their development time (28.00±01 Vs 37.00±01 day). Furthermore, mixing SCG diet with whey enhanced positively their performance by increasing the waste reduction (26.73±0.81 Vs 16.87±0.37 %), waste reduction index (0.85±0.03 Vs 0.45±0.01 %/day), approximate digestibility (36.49±1.52 Vs 20.29±0.53 %) and bioconversion rate (17.94±0.47 Vs11.65±0.52%). Adding whey to SCG diet increased protein content of BSFL (40.11% vs. 34.18%) and reduced fat (36.06 vs. 37.87 %) in dry mass. Whey also improved the composition of frass by increasing the phosphorus and total nitrogen levels. This approach demonstrates a sustainable solution for dairy industries waste, contributing to the circular economy and offering potential applications in animal feed and fertilizer production.

Bioconversion of faecal and kitchen waste using black soldier fly larvae (Hermetia illucens):

Novel technologies to convert faecal waste into valuable nutrients provide a win-win situation in enhancing the closed sanitation loop, and providing safe sanitation. In this study, laboratory-scale experiments were set to examine the applicability of the Black Soldier Fly in bioconversion of organic matter (faecal matter (FM) and kitchen waste (KW) while producing larvae biomass rich in protein and fat compounds. To determine the mass balance process, each of the feed substrates (500g) in triplicate and 3 grams of 6-day-old larvae (844 larvae) were introduced. The larval developmental time to 50% pupation, survival rate (SR), waste reduction rates (WR), prepupal yield, bioconversion rate (BCR), feed conversion rate (FCR), and efficiency of digested feed (ECD) were monitored in triplicate at the end of the experiments for mass balance process. Mass balance determination (triplicate) yielded average prepupal yield of 70.43±0.02g and 56.77±0.01g, with protein content per unit ranging from 32.23% to 41.26% and 20.06% to 37.13% on faecal and kitchen waste respectively. The ECD of 17.63±0.01% and 12.05±0.00%, waste reduction of 79.91% and 92.24% from faecal and kitchen waste respectively were obtained. From the findings, both substrates were palatable as BSFL feeds. The study findings show the potential of using BSF larvae technology to valorise faecal and kitchen waste and produce larval biomass rich in proteins and fats.

Waste Reduction and Bioconversion of Quail, Chicken, and Pig Manure by Black Soldier Fly (Hermetia illucens L.)

The increasing poultry and livestock farm operations have led to a great deal of manure generation. If inappropriately managed, it may cause adverse impacts on the environment, health, and economy. Black soldier fly (Hermetia illucens L.) larvae (BSFL) can potentially convert manure into protein-rich biomass and nutrient-rich frass effectively. In this study, BSFL were reared on three different waste streams – quail manure (QM), chicken manure (CM), and pig manure (PM). Manure mass was significantly reduced by larvae, of which QM had the highest overall degradation of 62.49% and waste reduction index of 10.42% (p-value < 0.05) of dry matter (DM). The larvae reared in QM also had the highest bioconversion rate (26.41%) and individual larval weight (~ 0.22 g/larva) (p < 0.05) with DM protein and fat contents of 54.77 and 13.79%, respectively, being a potentially high protein and high energy animal feed. Meanwhile, larvae reared in CM produced the lowest larval biomass (~ 0.07 g/larva) but had the most frass (252.10 g) (p < 0.05). However, there were no significant differences in the frass composition (organic matter, nitrogen-phosphorus-potassium, and carbon-to-nitrogen ratio) from the three substrates (p > 0.05). Therefore, BSFL presents a promising solution for efficient manure management by converting it into valuable frass and larval biomass with potential applications as plant fertilizer and animal feed ingredient, respectively.

Utilization of carbon catabolite repression for efficiently biotransformation of anthraquinone O-glucuronides by Streptomyces coeruleorubidus DM.

Carbon catabolite repression (CCR) is a highly conserved mechanism that regulates carbon source utilization in Streptomyces. CCR has a negative impact on secondary metabolite fermentation, both in industrial and research settings. In this study, CCR was observed in the daunorubicin (DNR)-producing strain Streptomyces coeruleorubidus DM, which was cultivated in high concentration of carbohydrates. Unexpectedly, DM exhibited a high ability for anthraquinone glucuronidation biotransformation under CCR conditions with a maximum bioconversion rate of 95% achieved at pH 6, 30°C for 24 h. The co-utilization of glucose and sucrose resulted in the highest biotransformation rate compared to other carbon source combinations. Three novel anthraquinone glucuronides were obtained, with purpurin-O-glucuronide showing significantly improved water solubility, antioxidant activity, and antibacterial bioactivity. Comparative transcript analysis revealed that glucose and sucrose utilization were significantly upregulated as DM cultivated under CCR condition, which strongly enhance the biosynthetic pathway of the precursors Uridine diphosphate glucuronic acid (UDPGA). Meanwhile, the carbon metabolic flux has significantly enhanced the fatty acid biosynthesis, the exhaust of acetyl coenzyme A may lead to the complete repression of the biosynthesis of DNR, Additionally, the efflux transporter genes were simultaneously downregulated, which may contribute to the anthraquinones intracellular glucuronidation. Overall, our findings demonstrate that utilizing CCR can be a valuable strategy for enhancing the biotransformation efficiency of anthraquinone O-glucuronides by DM. This approach has the potential to improve the bioavailability and therapeutic potential of these compounds, opening up new possibilities for their pharmaceutical applications.

Performance of feeding black soldier fly (Hermetia illucens) larvae on shrimp carcasses: A green technology for aquaculture waste management and circular economy

Over 944 thousand tonnes of shrimp carcasses are produced worldwide during the shrimp production cycle, and black soldier fly larvae (BSFL) are a potential solution for this shrimp carcass accumulation. In this study, we evaluated the performance of BSFL feeding on shrimp carcasses. Six combinations of wheat bran and shrimp carcass powder (with replacement increments of 20 %) and one whole shrimp carcasses treatment were tested. The bioconversion rate (27.15 ± 3.66 %; p = 0.001), crude protein (55.34 ± 1.27 %; p < 0.001), and crude lipid (14.37 ± 1.86 %; p = 0.007) values of BSFL reared on whole shrimp carcasses were significantly higher than those of BSFL reared on wheat bran. Increasing the shrimp carcass amount in the feeding media resulted in significant increases in BSFL docosahexaenoic acid (with the highest value occurring for BSFL reared on whole shrimp carcasses; 1.46 ± 0.09 %; p < 0.001). Conversely, BSFL docosahexaenoic acid was not detected for BSFL reared on wheat bran. The detected heavy metal concentrations in BSFL were below the limits of the published international guidelines for animal feed. In the obtained BSFL, Salmonella was not detected, and the mould count was <10 CFU/g. The total bacterial count (Lg transformation) of obtained BSFL ranged from 7.88 to 8.07 CFU/g, and no significant differences among all treatments (p = 0.424). Overall, this study demonstrates that BSFL-based bioconversion presents a resource recovery technology for converting shrimp carcasses into high-value nutritional biomass.

The fundamental role of pH in CH4 bioconversion into polyhydroxybutyrate in mixed methanotrophic cultures

Climate change and plastic pollution are likely the most relevant challenges for the environment in the 21st century. Developing cost-effective technologies for the bioconversion of methane (CH4) into polyhydroxyalkanoates (PHAs) could simultaneously mitigate CH4 emissions and boost the commercialization of biodegradable polymers. Despite the fact that the role of temperature, nitrogen deprivation, CH4:O2 ratio or micronutrients availability on the PHA accumulation capacity of methanotrophs has been carefully explored, there is still a need for optimization of the CH4-to-PHA bioconversion process prior to becoming a feasible platform in future biorefineries. In this study, the influence of different cultivation broth pH values (5.5, 7, 8.5 and 10) on bacterial biomass growth, CH4 bioconversion rate, PHA accumulation capacity and bacterial community structure was investigated in a stirred tank bioreactor under nitrogen deprivation conditions. Higher CH4 elimination rates were obtained at increasing pH, with a maximum value of 50.4 ± 2.7 g CH4·m−3·h−1 observed at pH 8.5. This was likely mediated by an increased ionic strength in the mineral medium, which enhanced the gas-liquid mass transfer. Interestingly, higher PHB accumulations were observed at decreasing pH, with the highest PHB contents recorded at a pH 5.5 (43.7 ± 3.4 %w·w−1). The strong selective pressure of low pH towards the growth of Type II methanotrophic bacteria could explain this finding. The genus Methylocystis increased its abundance from 34 % up to 85 and 90 % at pH 5.5 and 7, respectively. On the contrary, Methylocystis was less abundant in the community enriched at pH 8.5 (14 %). The accumulation of intracellular PHB as energy and carbon storage material allowed the maintenance of high CH4 biodegradation rates during 48 h after complete nitrogen deprivation. The results here obtained demonstrated for the first time a crucial and multifactorial role of pH on the bioconversion performance of CH4 into PHA.

The Efficiency of Black Soldier Fly Larvae with Vegetable, Fruit and Food Waste as Biological Tool for Sustainable Management of Organic Waste

This study investigated the sustainable management of wet organic waste using Black Soldier Fly Larvae (BSFL) for an innovative biological approach to waste management. The organic wet wastes such as fruit, vegetable, and food wastes were processed and fed to BSFL larvae from day 5 and the bioconversion process was carried out at Black Soldier Fly Unit, Tamil Nadu Agricultural University for 21 days. Among the three wastes, the highest bioconversion efficiency was recorded in fruit waste with 67% Substrate Reduction, 10.8% Efficiency of Conversion of Digested feed, 5.7% Bio Conversion Rate, and 4.18 Waste Reduction Index after 21 days. Whereas vegetable and food waste achieved similar bioconversion efficiency. The results suggest that BSFL-based bioconversion can be an effective and eco-friendly waste management and resource recovery technique to significantly lower the volumes of organic wet waste while converting it into high-value biomass and leading to a circular economy model.

Impact of chick mash, rice bran, and wheat bran as starter feeds on the performance of black soldier fly larvae in food waste treatment

ABSTRACT Inadequate management of food waste (FW) has contributed to environmental degradation. Bioconversion of FW using black soldier fly larvae has proven to be a safe and cost-effective method for FW management. However, limited studies exist on the influence of starter feeds. The impact of rice bran, wheat bran, and chick mash as starter feeds was evaluated by investigating the optimal larval weight, substrate reduction, feed conversion ratio (FCR), and bioconversion rate (BCR) of the larvae after initial treatment in rice bran (T1), wheat bran (T2), chick mash (T3), and control (T4). The highest mean larval weight observed was 0.22 g in T3 followed by 0.18, 0.16, and 0.13 g in T2, T4, and T1, respectively. A similar trend was observed for substrate reduction and BCR. Nevertheless, the obtained substrate reduction range of 75.5–82.8% was comparable with the published ranges. The best performance in T3 may be attributed to high protein and nitrogen content in chick mash, while the lowest performance is attributed to high ash content in rice bran, which negatively affected the BCR. It can be concluded that the physico-chemical properties of the starter feeds strongly determine the growth and development of larvae.

Enhancing the bioconversion rate and end products of black soldier fly (BSF) treatment – A comprehensive review

AbstractFood security remains a pressing concern in the face of an increasing world population and environmental challenges. As climate change, biodiversity loss, and water scarcity continue to impact agricultural productivity, traditional livestock farming faces limitations in meeting the growing global demand for meat and dairy products. In this context, black soldier fly larvae (BSFL) have emerged as a promising alternative for sustainable food production. BSFL possess several advantages over conventional livestock, including their rapid growth, adaptability to various organic waste substrates, and low environmental impact. Their bioconversion rate, the ability to transform organic waste into valuable products, and final product optimization are key factors that enhance their potential as a nutrient-rich protein source, fertilizer, and biofuel. This review explores strategies to enhance the bioconversion rate and improve the end products derived from BSF treatment. It highlights the benefits of using BSFL over other interventions and underscores the significance of optimizing their bioconversion rate to meet the challenges of global food security sustainably. Despite the promising prospects of BSF-derived products, consumer acceptance and regulatory hurdles remain critical aspects to address in realizing their full market potential. The utilization of BSFL as a sustainable source of food and feed can contribute to waste management, reduce environmental pollution, and address the pressing issue of food security in an environmentally responsible manner. However, there is a need for further research and innovation to ensure the safety, quality, and economic viability of BSF-based products for both animal and human consumption.

Применение бактерий со сверхэкспрессией гена cadA для биоконверсии лизина в кадаверин

The article is devoted to construction of an Escherichia coli strain with overexpression of the cadA gene encoding lysine decarboxylase, as well as to assessment of its ability to convert lysine to cadaverine depending on the pH of the medium. The overexpressing strain was constructed on the base of E. coli BL21DE3 strain transformed with the pET19b plasmid carrying the cadA gene from E. coli MC4100. Bacteria were grown in 5 mL of LB broth at 37 °C without stirring, overexpression of cadA was induced by the addition of 1 mM isopropyl-β-D-thiogalactopyranoside (at OD600 = 0.6), after 2 hours the cells were washed and transferred to a medium with pH 7.4 or 4.0 with the addition 5 g/L L-lysine hydrochloride. The amount of synthesized cadaverine was quantified by TLC with preliminary derivatization with dansyl chloride. The maximum rate of bioconversion was observed when cells overexpressing cadA were cultivated in a medium with pH 4.0 (2.8 ± 0.7 mmol cadaverine/g dry weight per hour). The rate of bioconversion under basal conditions (pH 7.4, basal expression) was 6.8 times lower. The final concentration of cadaverine when cultivated in a medium with pH 7.4 and/or in the absence of overexpression of the cadA gene was 0.8-1 mM; under conditions of overexpression of the gene, up to 1.2 mM of cadaverine accumulated in a neutral medium, and 1.8 mM in an acidic medium.

Bioconversion of organic wastes using black soldier fly

Experiment was conducted at Department of Entomology, University of Agricultural Science Dharwad, to evaluate feasibility to degrade organic wastes in laboratory condition. Organic wastes like Vegetable Waste (VW), Fruit Waste (FW), Unfed Crop Waste (UCW), Kitchen Waste (KW), VW + dung (3:1), FW + dung (3:1), UCW + dung (3:1), KW + dung (3:1) were added in tray with 700 maggots per tray. Organic wastes (feed) were supplied @ 220 mg/maggot/day and the total feed maintained was 500 g/tray which was sufficient for three days. Feed was supplied at three days interval up to 9th day and hence total feed used per tray was 1500 g. Results indicated that kitchen waste was significantly superior over the other treatments with high prepupal weight (317.97 mg/maggot), maximum bioconversion rate (14.56%) and high feed reduction rate (96.07%). The present study revealed that kitchen waste as feed for Black Soldier Fly, results in better pre pupal weight and higher waste reduction efficiency. Thus, the kitchen waste can be used for mass rearing of Black Soldier Fly to explore its potentiality as a bio agent for waste management.