Waste Substrates Research Articles

MFC Performance with Additional Micronutrients in Food Waste Substrate

Microbial Fuel Cell (MFC) are the one of utilization of waste for renewable energy continues to be developed. According to the FAO, 32% of all food for human consumption is discarded about 1.3 billion tonnes per year. In this study, Microbial Fuel Cells used an organic source in the form of food waste that had been hydrolyzed by Aspergillus oryzae, Aspergillus aculeatus, and Candida rugosa. The results of the hydrolysis are entered into the MFC system. In the MFC system it is mixed with Sidoarjo mud and Shewanella oneidensis MR-1, then put into a Single Chamber microbial fuel cell (SC-MFC) to generate electricity. In this research, also added micronutrients (Mg2+, Ni2+, Cu2+, Ca2+, Pb2+, Co2+, Cd2+, Cr2+, and Zn2+) to increase the metabolic of Shewanella oneidensis MR-1 bacteria, so can elevate electric currents. electrons and protons are produced by microorganisms by changing organic compounds in the substrate. The results showed that the best power density was 6.652 W/m2 with BOD 89.362% and COD removal 77.273% achieved with a ratio of food waste to water of 2:1 M. Food hydrolysis is capable of hydrolyzing 40% food waste into glucose within 24 hours. The greatest percentage of glucose decreased was achieved by Cobalt micronutrient addition with 77% of glucose decreased. Therefore, MFC can be greatly enhance food waste degradation to become a carbon source in a microbial fuel cell for electricity production.

Comparative studies on the cultivation, yield, and nutritive value of an edible mushroom, Pleurotus tuber-regium (Rumph. ex Fr.) Singer, grown under different agro waste substrates.

In the present study, Pleurotus tuber-regium (Rumph. ex Fr.) Singer collected from Keeriparai forest of Kanyakumari district, South India was cultivated using environmentally benign, low-cost agricultural waste residues (paddy straw, sugarcane bagasse, rice husk, and sawdust) as growth substrates. The main goal of this study was to assess the cultivation, yield, and nutritional value of P. tuber-regium fruiting bodies grown under different growth substrates. Spawn running time and time for primordia formation were found to be shorter in mushroom growing with paddy straw substrate compared to sawdust and sugarcane bagasse. A quick spawn run time was observed in paddy straw substrate (12 ± 1 day) followed by sugarcane bagasse (15 ± 1 day) and sawdust (23 ± 1 day). The primordia was well developed in the macrofungus grown with paddy straw substrate on 18 ± 1 day followed by sugarcane bagasse (22 ± 1 day) and sawdust (32 ± 1 day). Significantly higher yield of fruiting bodies with increased contents of protein and carbohydrate and low level of fat was obtained when P. tuber-regium was cultivated with paddy straw substrate. While, cultivation of P. tuber-regium in sawdust and sugarcane bagasse resulted in increased contents of K, Na, Ca, and Mg along with highest energy value. On the other hand, rice husk did not support the cultivation of this macrofungus. Therefore, it is of significant interest to initiate the commercial production of this macrofungus so as to fight against the problems of malnutrition found in few African and south Asian countries.

Enhancing the Fermentation Process in Biogas Production from Animal and Plant Waste Substrates in the Southeastern Region of Bulgaria

Annually, a huge amount of waste from plant biomass and animal manure is produced from agriculture and animal farming. Many studies provide information on the biomethane potential of agricultural and livestock wastes, but only a few studies have investigated the application of the substrates in combination. The objective of the study is to enhance the fermentation process in the digester for biogas production, obtained from animal and plant waste substrates. In four batch processes for three months, the temperatures and the residence time of the substrates in the fermenter were analyzed. Simultaneously, electricity and thermal energy were produced via cogeneration units, which were exported to the public grid and city heating network. The plant substrate is a silage mixture of corn and wheat waste. The animal substrate is a mixture of beef and pig manure. Animal and vegetable waste raw materials are collected and transported to the site, located in the region of southeastern Bulgaria. The total annual consumption of animal and plant waste is 17,971 t/year. The enhancement of the process leads to the production of 1,506,000 Nm3 CH4/a of methane, the generation of which requires 299.63 MWh/a of electricity and 649.09 MWh/a thermal energy.

Effect of Fruit Waste Substrate Concentration and pH on Biogas Production by Mixed Culture

Effect of Fruit Waste Substrate Concentration and pH on Biogas Production by Mixed Culture

Bioconversion of pineapple wastes for production of Pleurotus pulmonarius (gray oyster mushroom) and Pleurotus ostreatus (white oyster mushroom)

AbstractMushroom cultivation is currently being widely ventured by farmers in Malaysia due to its high profits in a short time and low production cost. Mushrooms can be grown on various substrates such as rice husk and stalks, coconut fiber, and sawdust. This study was performed to find out the ability of using pineapple leaves waste as a substrate for the cultivation of Pleurotus pulmonarius (gray oyster mushroom) and Pleurotus ostreatus (white oyster mushroom) and compare the results obtained with mushrooms grown using traditional substrates (sawdust). The mushroom bags were prepared using a dry and wet medium of pineapple leaves waste. The results revealed that 60% of dry and wet pineapple leaves waste produced the highest output of P. pulmonarius and P. ostreatus in comparison to other percentages. The growing of P. pulmonarius on dry pineapple leaves waste substrate revealed the maximum average weight and number of fruiting bodies while P. ostreatus showed the best growth performance in wet pineapple leaves waste substrate. The nutritional content of 60% dry and wet pineapple leaves waste for both P. pulmonarius and P. ostreatus shown superior value in percentages of moisture, protein, fat, and carbohydrate compared to control. In the meantime, the mineral analysis revealed that 60% of the dry and wet pineapple leaves waste had greater levels of Cu, P, and Pb than the control. These findings suggested that the pineapple leaves waste can become a great alternative substrate for both P. pulmonarius and P. ostreatus cultivation for better economic and environmental benefits.

BIOGAS PRODUCTION POTENTIAL FROM ANAEROBIC CO-DIGESTION OF FOOD WASTE AND ANIMAL MANURE

The potential of biogas production by the anaerobic codigestion (AcoD) of canteen food waste and animal manure was investigated using the biochemical methane potential assay (BMP). The BMP assay was conducted under thermophilic temperature of 35 °C in a batch process at digestion time of 40 d. Waste substrate mixture was digested at a fixed proportion of 1:1 with different animal manure as co-substrate. Maximum cumulative biogas production (418 ml g-1 VS) was achieved during codigestion of food waste with pig manure > chicken manure (408 ml g-1 VS) > goat manure (319 ml g-1 VS). Generally, all manure codigested reactors produced 1.01 to 1.34 times more biogas than food waste alone indicating the synergistic effect of codigestion on overall biogas productivity. With analogous increase in biogas production, manure amendment produced significant (p<0.05) substrate biodegradation in terms of total and volatile solids loss. The microbial load profile prior and post-AD revealed significant reduction (p<0.05)in microbial species suggestion that anaerobic digestion can be adopted as a method of waste treatment and hygienization.

Unlocking the Potential of Substrate Quality for the Enhanced Antibacterial Activity of Black Soldier Fly against Pathogens.

Globally, antibiotics are facing fierce resistance from multidrug-resistant bacterial strains. There is an urgent need for eco-friendly alternatives. Though insects are important targets for antimicrobial peptides, it has received limited research attention. This study investigated the impact of waste substrates on the production of antibacterial agents in black soldier fly (Hermetia illucens L.) larvae (HIL) and their implications in the suppression of pathogens [Bacillus subtilis (ATCC 6051), Staphylococcus aureus (ATCC 25923), Pseudomonas aeruginosa (ATCC 27853), and Escherichia coli (ATCC 25922)]. The 20% acetic acid (AcOH) extract from market waste had the highest antibacterial activity with an inhibition zone of 17.00 mm, followed by potato waste (15.02 mm) against S. aureus. Hexane extract from HIL raised on market waste also showed a significant inhibitory zone (13.06 mm) against B. subtilis. .Minimum inhibitory concentration (MIC) values recorded were 25 mg/mL against all test pathogens. The fastest time-kill of 20% AcOH extract was 4 h againstB. subtilis, E. coli, ,andP. aeruginosa. Lauric acid was also identified as the dominant component of the various hexane extracts with concentrations of 602.76 and 318.17 μg/g in HIL reared on potato and market waste, respectively. Energy from the market waste substrate correlated significantly (r = 0.97) with antibacterial activities. This study highlights the key role of substrate quality and extraction methods for enhancing the production of antibacterial agents in HIL, thus providing new insights into the development of potential drugs to overcome the alarming concerns of antimicrobial resistance.

Effect of Agroindustrial Waste Substrate Fermented with Lactic Acid Bacteria and Yeast on Changes in the Gut Microbiota of Guinea Pigs.

The aim of the study was to evaluate the impact of probiotics obtained from an agroindustrial waste substrate fermented with lactic acid bacteria and/or yeasts on the health and changes in the microbiota of the digestive tract of guinea pigs. Eighty male guinea pigs, Kuri breed, 30 days old and 250 g live weight, were randomly selected and divided into four groups of 20 animals each: T0, control; T1, Lactobacillus acidophilus and L. bulgaricus; T2, Saccharomyces cerevisiae and Kluyveromyces fragilis; and T3. L. acidophilus, L. bulgariccus, S. cerevisiae and K. fragilis. T1, T2 and T3 contained molasses-vinasse substrate in their base, the dose administered was 1.00 mL/animal orally every 3 days. The indicators evaluated were weight gain, occurrence of diarrhea and mortality, macroscopic lesions in the digestive tract organs and changes in the microbiota of the stomach, caecum, small and large intestine. Treatments T1, T2 and T3 improved weight gain (p < 0.05) and reduced the presence of guinea pigs with diarrhea (p < 0.05) and there was no mortality; animals in the control group presented a greater amount (p < 0.05) of macroscopic lesions in the digestive tract organs; in the T1, T2 and T3 groups there was an improvement in the natural microbiota. It is concluded that the inclusion of a microbial additive in young guinea pigs improves intestinal health and consequently improves weight gain, reduces diarrhea and deaths and normalizes the natural microbiota of the gastrointestinal tract.

Screening of Microorganisms from Wastes and Identification of the Optimal Substrate for Biosurfactant Production

The production of biosurfactants from organic wastes has received significant attention due to its potential cost savings. This study involved the isolation of biosurfactant-producing microorganisms from waste sources. The surfactant properties of the 37 studied isolates were assessed by reducing surface tension and their emulsifying properties, determined by the emulsification index E24. We assessed the ability of these isolated strains to produce biosurfactants using various waste substrates, namely potato peelings, waste cooking oil and sunflower cake. Our results showed that sunflower cake exhibited better growth and biosurfactant production for most of the strains studied. This highlights that sunflower cake is a potentially effective and economical substrate for the production of biosurfactants. The most effective strains allowing to achieve an emulsification index above 50% and reduce surface tension below 40 mN m−1 were Enterobacter sp. 2pp, strain 2wfo, Peribacillus sp. 1mo, Sphingomonas sp. 2mo, Ochrobactrum sp. 5mo, Shouchella sp. 6mo, Bacillus sp. 1os, Bacillus sp. 2os. Among these strains, both previously known strains as biosurfactant producers and previously unknown strains were found. Thus, we found that among representatives of the genus Sphingomonas there are effective producers of biosurfactants. The highest yield of biosurfactant on a medium with glycerol and glucose was shown by the Bacillus sp. 2os strain of 0.501 and 0.636 g L−1, respectively.

Comparative analysis of hydrogen production and bacterial communities in mesophilic and thermophilic consortia using multiple inoculum sources

This study investigates the hydrogen (H2) production performance and bacterial communities in mesophilic (37 °C) and thermophilic (50 °C) H2-producing consortia derived from different inoculum sources and utilizing food waste as a substrate. This study found notable variations in H2 production characteristics among these consortia. Among the mesophilic consortia (MC), the W-MC obtained with wetland (W) as the inoculum source exhibited the highest hydrogen production (3900 mL·L−1 and 117 mL·L−1·h−1), while among the thermophilic consortia (TC), the FP-TC obtained with forest puddle sediment (FP) as the inoculum source showed the highest performance (2112 mL·L−1 and 127 mL·L−1·h−1). This study reveals that the choice of inoculum source plays a crucial role in determining hydrogen production efficiency. Furthermore, the bacterial community analysis demonstrated varying microbial diversity and richness in different inoculum sources. Clostridium, a well-known H2-producing bacterium, was found in both mesophilic and thermophilic consortia and showed a positive correlation with H2 production. Other bacteria, such as Sporanaerobacter, Caproiciproducens, and Caldibacillus, also exhibited significant correlations with H2 production, suggesting their potential roles in the process. The study highlights the complex interactions between bacterial communities and hydrogen production performance, shedding light on the critical factors influencing this renewable energy source. Overall, this study contributes to our understanding of the microbial ecology and the factors affecting hydrogen production in different temperature conditions, which can have practical implications for optimizing biohydrogen production processes using organic waste substrates.

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.

The Potential of Lignocellulosic Biomass Hydrolysates for Microbial Oil Production Using Yeasts and Microalgae

The use of food‐based biomass and arable land for bio‐oil and biofuel production could compromise global food security. Therefore, renewable and environmentally friendly oils for biofuels from oleaginous microorganisms such as yeasts and microalgae (heterotrophic and mixotrophic) are gaining interest within the scientific community. These microorganisms have shorter cultivation times and higher lipid productivity when compared to higher plants/food crops/autotrophic microorganisms. Despite many advantages, the high carbon requirements and production cost are limiting factors that hinder their deployment at a commercial scale. Lignocellulosic waste substrates are abundant and inexpensive materials that are rich in organic carbon in the form of cellulose and hemicellulose, which release bioavailable forms of sugars upon hydrolysis. Recent studies have shown the tremendous potential of the hydrolysates of these substrates to be utilized as carbon sources for biomass production and the accumulation of lipids in oleaginous hetero‐/mixotrophic microorganisms. Therefore, this review highlights the potential use of lignocellulosic biomass as a low‐cost carbon substrate for the cultivation of hetero‐/mixotrophic microalgae and yeast for microbial oil production for commercial applications. It also examines the current status, challenges, and future prospects for the utilization of lignocellulose biomass.

Integrated biorefinery strategy for poly(3-hydroxybutyrate) accumulation in Cupriavidus necator DSM 545 using a sugar rich syrup from cereal waste and acetate from gas fermentation

Poly(3-hydroxybutyrate) (PHB) is one of the most well-known biodegradable and biocompatible biopolymers produced by prokaryotic microorganisms. It belongs to the family of polyhydroxyalkanoates (PHAs), and it has gained significant attention in recent years due to its potential as a sustainable alternative to traditional petroleum-based plastics. Cupriavidus necator has been identified as a potential producer of PHB for industrial applications due to its ability to produce high amounts of the polymer under controlled conditions, using a wide range of waste substrates. In this study, the ability of Cupriavidus necator DSM 545 strain to produce PHB was tested in a fed-batch strategy providing two different organic substrates. The first is a sugar-based syrup (SBS), derived from cereal waste. The second is an acetate-rich medium obtained through CO2 -H2 fermentation by the acetogenic bacterium Acetobacterium woodii. The carbon sources were tested to improve the accumulation of PHB in the strain. C. necator DSM 545 proved to be able to grow and to perform high accumulation of biopolymer on waste substrates containing glucose, fructose, and acetate, reaching about 10 g/L of PHB, 83% of biopolymer accumulation in cell dry mass, in 48 h of fed-batch fermentation in 0.6 L working volume in a bioreactor. Moreover, a Life Cycle Assessment analysis was performed to evaluate the environmental impact of the process converting the sugar syrup alone and the integrated one. It demonstrated that the integrated process is more sustainable and that the most impactful step is the PHB production, followed by the polymer extraction.

Novel Bioformulations with Trichoderma lixii to Improve the Growth Dynamics and Biocontrol of the Cowpea Damping-Off Disease

Because agricultural wastes are abundant in biologically active substances, they can be used as a substitute source to produce highly valuable products while lowering pollution levels in the environment. Therefore, we aimed at determining the best agricultural wastes to increase the biomass production rate and the effectiveness of the biocontrol strain Trichoderma lixii SARS 111 in a solid-state fermentation system. The potential for its use in enhancing growth dynamics and controlling the Fusarium oxysporum NCAIM-F-00779-caused damping-off disease of cowpea plants grown in greenhouse conditions was also studied. Using a one-factor-at-a-time experiment, five cheap agricultural waste substrates (faba bean, cowpea, sweet potato, pumpkin, and cassava) were studied using the Plackett–Burman design (PBD) and the central composite design (CCD) to optimize the nutritional and growth conditions to maximize the production of Trichoderma conidia. The findings demonstrated that increasing Candida production quantitatively required the use of 3 g of sweet potato, 3 g of cassava, pH 6, 25 °C, and pre-treatment with dH2O. The shelf life and viability of T. lixii strain were measured as log10 CFU g−1 per substrate at room temperature (RT, 25 °C) at the beginning of month 0 and subsequently at 2-month intervals for 12 months. Data showed that the fungal counts increased with the use of 4 g of sweet potato + 2 g of cassava up to 7 months and then sharply decreased, lasting up to 12 months. Additionally, this bioformulation was applied to cowpea plants in a greenhouse experiment, where a significantly higher level of plant growth traits, photosynthetic pigments, antioxidant enzymes, and chemical content in the leaves, as well as lower incidence of the damping-off disease, were noted. Accordingly, it is possible to suggest 4 g of sweet potato and 2 g of cassava as a suitable bioformulation for the industrial-scale production of the T. lixii strain, which may be a potential biocontrol agent for preventing the cowpea damping-off disease caused by F. oxysporum and improving the growth dynamics.

Valorization of coconut and banana wastes with petcoke and coal via steam gasification in a fluidized bed reactor

Steam gasification experiments were conducted with coal and petcoke in conjunction with potentially renewable biomass substances, namely coconut shell, coconut husk, and banana peduncle, which are usually considered waste materials. The gasification performance in a bench-scale externally heated fluidized bed gasifier was evaluated based on the product syngas quality and the detailed characterization of feed and product samples using X-ray fluorescence (XRF), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy analysis. This work performed experiments at relatively constant operating parameters: solid feed rate, steam/O2 ratio, feed particle size, and gasification reactor temperature. Biomass waste resources showed an augmentation in the syngas product quality for both the coal and petcoke samples, especially in cold gas efficiency (CGE) and carbon conversion efficiency (CCE). A maximum increase in CCE from 44.3 % to 72 % for the coal sample and from 19.3 % to 36.0 % for the petcoke sample was witnessed, whereas for the CGE, a rise of 35.8 %–91.7 % for the coal and 44.3 %–59.8 % for the petcoke with 80/20 blended biomass waste samples, was observed compared to the coal and petcoke only samples. The maximum hydrogen product gas yield between 53 and 73.7 vol % and combustible gas yields between 62.2 and 86.7 vol % were obtained on a nitrogen gas-free basis during the experiments. The solid residues of different gasification experiments were characterized and analyzed by scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) and field emission-scanning electron microscopy (FE-SEM) analytical techniques to elucidate the high yield of energy-intensive gases. FTIR analysis was performed on all the liquid product samples obtained during the gasification experiments. The presence of alkali and alkaline earth metals (AAEMs) in biomass wastes highlighted the catalytic effect of these elements during the gasification experiments. The current work provides an opportunity to reduce carbon footprints with effective and efficient utilization of conventional energy feedstocks in conjunction with other waste substrates.

Development of Microbial Fuel Cell in Tofu Liquid Waste in Producing Clean Energy

The high need of Indonesian people for electrical energy has led to an increase in energy demand. This has triggered research efforts based on renewable technologies that are efficient and environmentally friendly. One of the renewable energy sources that is widely developed is Microbial Fuel Cell (MFC). MFC works by utilizing organic matter used by microbes as an energy source in carrying out metabolic activities. This study aims to determine the effect of Bacillus subtilis and Escherichia coli bacteria with different concentrations of 10% (v/v) and 15% (v/v) on the electrical energy generated from the tofu liquid waste substrate and observe changes in pH and Biological Oxygen Demand (BOD) in the MFC system. This research method consists of several steps, namely the preparation of electrolysis equipment, electrodes, substrates, bacterial cultures, electrolytes and MFC processes. The maximum value of voltage and current in Bacillus subtilis bacteria occurred at the 10 hours with 15% (v/v) bacterial concentration which amounted to 394 mV and 10.6 mA with a bacterial population of 16.15 × 109 CFU/mL and a power density value of 126.67 × 10-4 watt/m2. Furthermore, the maximum value for Escherichia coli bacteria occurred at the 10 hours with a voltage and current of 266 mV and 5.3 mA with a bacterial population of 15.60 × 109 CFU/mL and a power density value of 55.67 × 10-4 watts/m2. The pH value of the substrate variations with the addition of Bacillus subtilis bacteria ranged from 5-6, while with the addition of Escherichia coli bacteria variations ranged from 4-5. This system also reduces the value of biological oxygen demand.

Versatile Applications of Brewer's Spent Grain: Solid-State Fermentation and Nutritional Added Value.

Brewer's spent grain (BSG) is a major by-product in the beer-brewing process which contributes to 85% of the entire generated by-product in the brewing process. BSG is rich in proteins, and most of the malt proteins (74-78%) remain insoluble in BSG after the mashing process. Solid-state fermentation (SSF) is a promising bioprocess that enables microorganisms to survive in environments with minimal water and has shown to enhance the nutritional composition of BSG. In this review, the potential application of protein, amino acids (proline, threonine, and serine), phenolic contents, and soluble sugars (glucose, fructose, xylose, arabinose, and cellobiose) extracted from BSG by various microorganisms using SSF is explored. Incorporation of BSG into animal feed, human diets, and as a substrate for microorganisms are the prospects that could be implemented in the industrial scale. This review also discussed various advances to improve the fermentation yield such as symbiotic fermentation, the addition of nitrogen supplements, and an optimal mixture of the agro-industrial waste substrate. Future perspectives on SSF are also addressed to provide important ideas for immediate and future studies. However, challenges include optimizing SSF conditions and design of bioreactors, and operational costs must be addressed in the future to overcome current obstacles. Overall, this mini review highlights the potential benefits of BSG utilization and SSF in a sustainable way.

Upcycling of food waste generated from the fresh market by utilising black soldier fly larvae: Influence on growth, bioconversion, and nutritional composition

Innovative solutions are needed to limit environmental effect and optimise resource use as food waste generation rises worldwide. This study investigates the potential of upcycling food waste from fresh markets using Black Soldier Fly (Hermetia illucens) larvae (BSFL) as a sustainable approach. This study explored four fresh market food waste substrates for BSFL bioconversion: discarded fish waste (FI), slaughtered chicken waste (CHI), vegetable waste (VEG), and a 1:1:1 combination of all three (MIX). Soybean curd residue (SCR) was treated as the control substrate. The effects on larval growth, nutritional content, and waste bioconversion rates were examined. The larvae growth rate was strongly impacted by waste type, with BSF-fed CHI and MIX gaining 18.0 and 16.7 mg/d, respectively, followed by BSF-fed with SCR (12.2 mg/d), FI (8.9 mg/d) and VEG (7.6 mg/d). The waste type did not substantially alter BSFL length. The survival rate of the BSFL fed with the food waste studied ranges from 95 to 98.47%, with SCR being the highest. Our findings indicated that BSFL can effectively convert a variety of fresh market food waste into valuable biomass. CHI waste produced the highest larval biomass and bioconversion rate followed by MIX, SCR, FI and VEG. The different waste stream has a major influence on BSFL biomass nutrition. BSFL nutritional composition is independent of the substrate’s nutritional content, indicating no direct correlation between substrate and BSFL biomass nutritional composition. SCR waste produced the highest protein content of BSFL (50.49%), followed by VEG (32.61%), MIX (32.57%), FI (31.03%) and CHI (29.06%). SCR waste also produced BSFL biomass with lowest lipid content (26.55%) compared to other waste which resulted into BSFL with lipid levels ranging from 42.92% to 53.72%. BSFL-fed with SCR is the most suitable to be used as an alternative animal’s feed based on the protein and lipid levels, while defatting procedure is necessary for the other waste-fed BSFL to render it suitability as animal feed alternatives. Based on bioconversion rate, BSFL growth, and lipid content, the MIX and CHI waste might be viable substrates for future research.

Production and Evaluation of Pleurotus spp. Hybrids Cultivated on Ecuadorian Agro-Industrial Wastes: Using Multivariate Statistical Methods

The sustainable management of agricultural residues is a pivotal element in ensuring the sustainable development of agriculture. This is based on strategies that include the reutilization of residues as a substrate for the cultivation of economically significant mushroom species. The primary aim of this investigation is to assess the viability of utilizing two of the most prevalent agricultural residues in Ecuador as a substrate for the cultivation of hybrids within the Pleurotus genus. This assessment includes an evaluation of the nutritional and productivity parameters exhibited by the resulting mushrooms, employing multivariate statistical methodologies. The hybrid strains were developed by crossing compatible neohaplonts obtained through chemical dedikaryotization. A total of five neohaplonts of Pleurotus ostreatus as parental strain P1 and five monokaryons of Pleurotus djamor as parental strain P2 were randomly crossed in all possible combinations. Two parental hybrid strains, H1 and H2, were produced. These hybrids were cultivated using agricultural waste substrates, specifically, green banana leaves (GBL) and sugarcane bagasse (SB). Two distinct treatments or mixtures were tested: M1 (composed of 80% SB and 20% GBL) and M2 (composed of 20% SB and 80% GBL). It was found that the M1 blend promotes mushroom growth, yielding superior properties attributable to the higher proportion of nutritional content derived from sugarcane bagasse.

Optimised extraction of phospholipids and omega‐3 fatty acids from Patagonian squid waste with low‐toxicity solvents

SummaryExtracting conditions of lipid compounds (phospholipids, PLs; ω3 fatty acids, FAs) from Patagonian squid (Doriteuthis gahi) waste were optimised by employment of a Simplex‐Lattice design. For it, different concentrations of low‐toxicity solvents (ethanol, acetone and ethyl acetate; single and binary and ternary mixtures) were tested. As a result, the multiple regression anova proved that the quadratic model was significant (P &lt; 0.05) for PL and eicosapentaenoic acid (EPA) contents and for total polyunsaturated/total saturated and total ω3/total ω6 FA ratios. Thus, the anova application of the fitting model led to the following optimised values for such parameters: 477.42 g kg−1 lipids, 21.48 g 100 g−1 total FAs, 3.48 and 13.03, respectively. The combination of process variable levels which maximised the desirability function (0.49 value) was ethanol/ethyl acetate (0.50:0.50, v/v) and led to values of 412.50 (g kg−1 lipids), 19.05 (g 100 g−1 total FAs), 2.59 and 12.86, respectively, for the above‐mentioned lipid parameters. Results were compared to those obtained by the conventional chloroform/methanol procedure. By including an advanced mathematical design, a novel eco‐friendly strategy based on the employment of low‐toxicity solvents is proposed for the extraction from a marine waste substrate of highly valuable lipid compounds with healthy and nutritional properties.