Gut Microbiome Associating with Carbon and Nitrogen Metabolism during Biodegradation of Polyethene in Tenebrio larvae with Crop Residues as Co-Diets

Effects of straw structure and component on feeding efficiency of yellow mealworm for insect protein production

Elucidating the influence of straw structure and component on the feeding efficacy of yellow mealworm is pivotal for improving insect protein production from straw. This research utilized four distinct types of straws-water hyacinth straw (WHS), corn straw (CS), rape straw (RAS), and rice straw (RIS)-as the sole substrate for larvae. Results indicated that the straw utilization rate and fresh larval weight gain rate followed the order of WHS > CS > RAS > RIS. Analysis of straw structural characteristics demonstrated that decreasing straw hardness and cellulose crystallinity, while enhancing straw chewability, facilitated the ingestion of larvae. Feeding efficiency of yellow mealworm was positively correlated with the hemicellulose and crude protein content, and inversely correlated with lignin content in the straw. Additionally, the structural characteristics and components of straw significantly influenced the composition of the gut microbiota. These results offer valuable insights for optimizing yellow mealworm feeding on straw.

Effects of plastic aging on biodegradation of polystyrene by Tenebrio molitor larvae: Insights into gut microbiome and bacterial metabolism

Plastics aging reduces resistance to microbial degradation. Plastivore Tenebrio molitor rapidly biodegrades polystyrene (PS, size: < 80 μm), but the effects of aging on PS biodegradation by T. molitor remain uncharacterized. This study examined PS biodegradation over 24 days following three pre-treatments: freezing with UV exposure (PS1), UV exposure (PS2), and freezing (PS3), compared to pristine PS (PSv) microplastic. The pretreatments deteriorated PS polymers, resulting in slightly higher specific PS consumption (602.8, 586.1, 566.7, and 563.9 mg PS·100 larvae-1·d-1, respectively) and mass reduction rates (49.6 %, 49.5 %, 49.2 %, and 48.7 %, respectively) in PS1, PS2, and PS3 compared to PSv. Improved biodegradation correlated with reduced molecular weights and the formation of oxidized functional groups. Larvae fed more aged PS exhibited greater gut microbial diversity, with microbial community and metabolic pathways shaped by PS aging, as supported by co-occurrence network analysis. These findings indicated that the aging treatments enhanced PS biodegradation by only limited extent but impacted greater on gut microbiome and bacterial metabolic genes, indicating that the T. molitor host have highly predominant capability to digest PS plastics and alters gut microbiome to adapt the PS polymers fed to them.

Cockroach Blaptica dubia biodegrades polystyrene plastics: Insights for superior ability, microbiome and host genes

The report demonstrated that a member of cockroach family, Blaptica dubia (Blattodea: Blaberidae) biodegraded commercial polystyrene (PS) plastics with Mn of 20.3 kDa and Mw of 284.9 kDa. The cockroaches digested up to 46.6 % of ingested PS within 24 h. The biodegradation was confirmed by the 13C isotopic shift of the residual PS in feces versus pristine PS (Δ δ13C of 2.28 ‰), reduction of molecular weight and formation of oxidative functional groups in the residual PS. Further tests found that B.dubia cockroaches degraded all eight high purity PS microplastics with low to ultra-high molecular weights (MW) at 0.88, 1.20, 3.92, 9.55, 62.5, 90.9, 524.0, and 1040 kDa, respectively, with superior biodegradation ability. PS depolymerization/biodegradation pattern was MW-dependent. Ingestion of PS shifted gut microbial communities and elevated abundances of plastic-degrading bacterial genes. Genomic, transcriptomic and metabolite analyses indicated that both gut microbes and cockroach host contributed to digestive enzymatic degradation. PS plastic diet promoted a highly cooperative model of gut digestive system. Weighted gene co-expression network analysis revealed different PS degradation patterns with distinct MW profiles in B. dubia. These results have provided strong evidences of plastic-degrading ability of cockroaches or Blaberidae family and new understanding of insect and their microbe mediated biodegradation of plastics.

Microplastics Biofragmentation and Degradation Kinetics in the Plastivore Insect Tenebrio molitor

The insect Tenebrio molitor possesses an exceptional capacity for ultrafast plastic biodegradation within 1 day of gut retention, but the kinetics remains unknown. Herein, we investigated the biofragmentation and degradation kinetics of different microplastics (MPs), i.e., polyethylene (PE), poly(vinyl chloride) (PVC), and poly(lactic acid) (PLA), in T. molitor larvae. The intestinal reactions contributing to the in vivo MPs biodegradation were concurrently examined by utilizing aggregated-induced emission (AIE) probes. Our findings revealed that the intestinal biofragmentation rates essentially followed the order of PLA > PE > PVC. Notably, all MPs displayed retention effects in the intestine, with PVC requiring the longest duration for complete removal/digestion. The dynamic rate constant of degradable MPs (0.2108 h-1 for PLA) was significantly higher than that of persistent MPs (0.0675 and 0.0501 h-1 for PE and PVC, respectively) during the digestive gut retention. Surprisingly,T. molitor larvae instinctively modulated their internal digestive environment in response to in vivo biodegradation of various MP polymers. Esterase activity and intestinal acidification both significantly increased following MPs ingestion. The highest esterase and acidification levels were observed in the PLA-fed and PVC-fed larvae, respectively. High digestive esterase activity and relatively low acidification levels inT. molitor larvae may, to some extent, contribute to more efficient MPs removal within the plastic-degrading insect. This work provided important understanding of MPs biofragmentation and intestinal responses to in vivo MPs biodegradation in plastic-degrading insects.

Generation and Fate of Nanoplastics in the Intestine of Plastic-Degrading Insect (Tenebrio molitor Larvae) during Polystyrene Microplastic Biodegradation

The insect Tenebrio molitor exhibits ultrafast efficiency in biodegrading polystyrene (PS). However, the generation and fate of nanoplastics (NPs) in the intestine during plastic biodegradation remain unknown. In this study, we investigated the biodegradation of PS microplastics (MPs) mediated by T. molitor larvae over a 4-week period and confirmed biodegradation by analyzing Δδ13C in the PS before and after biotreatment (-28.37‰ versus -24.88‰) as an effective tool. The ·OH radicals, primarily contributed by gut microbiota, and H2O2, primarily produced by the host, both increased after MP digestion. The size distribution of residual MP particles in excrements fluctuated within the micrometer ranges. PS NPs were detected in the intestine but not in the excrements. At the end of Weeks 1, 2, 3, and 4, the concentrations of PS NPs in gut tissues were 3.778, 2.505, 2.087, and 2.853 ng/lava, respectively, while PS NPs in glands were quantified at 0.636, 0.284, and 0.113 ng/lava and eventually fell below the detection limit. The PS NPs in glands remained below the detection limit at the end of Weeks 5 and 6. This indicates that initially, NPs generated in the gut entered glands, then declined gradually and eventually disappeared or possibly biodegraded after Week 4, associated with the elevated plastic-degrading capacities of T. molitor larvae. Our findings unveil rapid synergistic MP biodegradation by the larval host and gut microbiota, as well as the fate of generated NPs, providing new insights into the risks and fate associated with NPs during invertebrate-mediated plastic biodegradation.

Responses of physiological, microbiome and lipid metabolism to lignocellulose wastes in gut of yellow mealworm (Tenebrio molitor)

There is limited research on physiological and degradation mechanisms of yellow mealworm, a novel organic waste converter, in processing lignocellulosic wastes. This study has selected two types of lignocellulosic wastes, distillers' grains (DG) and maize straw (MS), to feed yellow mealworms. This study investigated the effects of lignocellulosic wastes on the growth, antioxidant system, microbiome, and lipidome of yellow mealworms. The relative growth of lignocellulosic waste group was not significantly different from wheat bran. The antioxidant level was elevated in DG. MS was significantly enriched in cellulose-degrading bacteria in the gut and was accompanied by disturbances in lipid metabolism. The correlation coefficients were used to construct a network connecting diet, microbiota, and lipids. The correlation analysis indicated that two sphingolipids, hexylglyceramide and dihydroglyceramide, were strongly and positively linked with the dominating species. This study provides comprehensive information on physiological and mechanism of mealworms in process of treating lignocellulosic waste.

Biodegradation of various grades of polyethylene microplastics by Tenebrio molitor and Tenebrio obscurus larvae: Effects on their physiology

Polyethylene (PE) is the most productive plastic product and includes three major polymers including high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE) and low-density polyethylene (LDPE) variation in the PE depends on the branching of the polymer chain and its crystallinity. Tenebrio obscurus and Tenebrio molitor larvae biodegrade PE. We subsequently tested larval physiology, gut microbiome, oxidative stress, and PE degradation capability and degradation products under high-purity HDPE, LLDPE, and LDPE powders (<300 μm) diets for 21 days at 65 ± 5% humidity and 25 ± 0.5 °C. Our results demonstrated the specific PE consumption rates by T. molitor was 8.04-8.73 mg PE ∙ 100 larvae-1⋅day-1 and by T. obscurus was 7.68-9.31 for LDPE, LLDPE and HDPE, respectively. The larvae digested nearly 40% of the ingested three PE and showed similar survival rates and weight changes but their fat content decreased by 30-50% over 21-day period. All the PE-fed groups exhibited adverse effects, such as increased benzoquinone concentrations, intestinal tissue damage and elevated oxidative stress indicators, compared with bran-fed control. In the current study, the digestive tract or gut microbiome exhibited a high level of adaptability to PE exposure, altering the width of the gut microbial ecological niche and community diversity, revealing notable correlations between Tenebrio species and the physical and chemical properties (PCPs) of PE-MPs, with the gut microbiome and molecular weight change due to biodegradation. An ecotoxicological simulation by T.E.S.T. confirmed that PE degradation products were little ecotoxic to Daphnia magna and Rattus norvegicus providing important novel insights for future investigations into the environmentally-friendly approach of insect-mediated biodegradation of persistent plastics.

Molecular-Weight-Dependent Degradation of Plastics: Deciphering Host-Microbiome Synergy Biodegradation of High-Purity Polypropylene Microplastics by Mealworms

The biodegradation of polypropylene (PP), a highly persistent nonhydrolyzable polymer, by Tenebrio molitor has been confirmed using commercial PP microplastics (MPs) (Mn 26.59 and Mw 187.12 kDa). This confirmation was based on the reduction of the PP mass, change in molecular weight (MW), and a positive Δδ13C in the residual PP. A MW-dependent biodegradation mechanism was investigated using five high-purity PP MPs, classified into low (0.83 and 6.20 kDa), medium (50.40 and 108.0 kDa), and high (575.0 kDa) MW categories to access the impact of MW on the depolymerization pattern and associated gene expression of gut bacteria and the larval host. The larvae can depolymerize/biodegrade PP polymers with high MW although the consumption rate and weight losses increased, and survival rates declined with increasing PP MW. This pattern is similar to observations with polystyrene (PS) and polyethylene (PE), i.e., both Mn and Mw decreased after being fed low MW PP, while Mn and/or Mw increased after high MW PP was fed. The gut microbiota exhibited specific bacteria associations, such as Kluyvera sp. and Pediococcus sp. for high MW PP degradation, Acinetobacter sp. for medium MW PP, and Bacillus sp. alongside three other bacteria for low MW PP metabolism. In the host transcriptome, digestive enzymes and plastic degradation-related bacterial enzymes were up-regulated after feeding on PP depending on different MWs. The T. molitor host exhibited both defensive function and degradation capability during the biodegradation of plastics, with high MW PP showing a relatively negative impact on the larvae.

Biodegradation of polystyrene microplastics by superworms (larve of Zophobas atratus): Gut microbiota transition, and putative metabolic ways

Superworm (larve of Zophobas atratus) could consume foams of expanded polystyrene plastics. However, there is no sufficient understanding of the impact of microplastics on superworms and the degradation pathways of polystyrene. Herein, we explored the weight and survival change of superworms while fed with polystyrene microplastics, and found that survival rate and mean weight would reduce. In terms of gut microbial community structure of surperworms, significant shifts were detected with the relative abundance of Hafnia-Obesumbacterium sp. increasing. In addition, we domesticated two microbiota from the gut of superworms, and confirmed their ability to degrade PS in vitro. The last but most important, 1291 metabolites were identified by HPLC-TOF-MS/MS, and six metabolites related to polystyrene degradation were identified through comparative metabolomic analysis. According to the content and pathways of these metabolites, three metabolic pathways of polystyrene were (a) styrene-phenylacetyl-CoA-L-2-aminoadipic acid; (b) styrene-phenylacetyl-CoA-benzaldehyde; (c) styrene-2-hydroxyacetophenone. These results would help to further screen bacteria of PS degradation and investigate PS metabolic pathways in invertebrates.

Biohydrogen production through energy efficient surfactant induced microwave pretreatment of macroalgae Ulva reticulata

Macroalgal biomass being rich in carbohydrates, proteins and lipids in their cell wall has been considered as the most efficient organic rich sources for biofuel (biohydrogen) production. In this study, Pluronic P-123-induced microwave pretreatment was applied to disintegrate the marine macroalgae biomass, Ulva reticulata. Microwave disintegration was done by varying the treatment time and microwave power from 0 to 40 min and 0.09 KW to 0.63 KW. A maximum chemical oxygen demand (COD) solubilization of 22.33% was achieved at a microwave power and time duration of 0.36 kW and 15 min. Chemical (Pluronic P-123, a mild surfactant) was combined with optimum microwave disintegration conditions to increase the solubilization efficiency and this combined pretreatment achieved a maximum COD solubilization of 31.02% at 10 min pretreatment time and 0.06 g per g TS of Pluronic P-123 dosage. The present study indicated that combination of surfactant with microwave pretreatment substantially improves the COD solubilization with reduced pretreatment -time than mono microwave pretreatment. An optimal hydrogen yield of 98.37 mL was achieved through this combined pretreatment. The biohydrogen data was modelled with Gompertz model and the kinetic parameters derived through this model implies that the calculated adjusted R squared values for all the samples lies between 0.95 and 0.99. This shows that the model fitted biohydrogen experimental values accurately. In addition, Pluronic P-123-induced microwave pretreatment was regarded as energy efficient and cost effective than microwave pretreatment alone with net energy production and a greater energy ratio of 504.38 kWh/Ton macroalgae and 1.2 when compared to microwave pretreatment alone (-2975.6 kWh/Ton macroalgae and 0.5).

Panorama of biogenic nano-fertilizers: A road to sustainable agriculture

The ever-increasing demand for food from the growing population has augmented the consumption of fertilizers in global agricultural practices. However, the excessive usage of chemical fertilizers with poor efficacy is drastically deteriorating ecosystem health through the degradation of soil fertility by diminishing soil microflora, environment contamination, and human health by inducing chemical remnants to the food chain. These challenges have been addressed by the integration of nanotechnological and biotechnological approaches resulting in nano-enabled biogenic fertilizers (NBF), which have revolutionized agriculture sector and food production. This review critically details the state-of-the-art NBF production, types, and mechanism involved in cultivating crop productivity/quality with insights into genetic, physiological, morphological, microbiological, and physiochemical attributes. Besides, it explores the associated challenges and future routes to promote the adoption of NBF for intelligent and sustainable agriculture. Furthermore, diverse applications of nanotechnology in precision agriculture including plant biosensors and its impact on agribusiness and environmental management are discussed.

Microplastics (≤ 10 μm) bioaccumulation in marine sponges along the Moroccan Mediterranean coast: Insights into species-specific distribution and potential bioindication

Microplastics (MPs) are pervasive in marine environments and widely recognized as emerging environmental pollutants due to the multifaceted risks they exert on living organisms and ecosystems. Sponges (Phylum Porifera) are essential suspension-feeding organisms that may be highly susceptible to MPs uptake due to their global distribution, unique feeding behavior, and sedentary lifestyle. However, the role of sponges in MP research remains largely underexplored. In the present study, we investigate the presence and abundance of MPs (≤10 μm size) in four sponge species, namely Chondrosia reniformis, Ircinia variabilis, Petrosia ficiformis, and Sarcotragus spinosulus collected from four sites along the Mediterranean coast of Morocco, as well as their spatial distribution. MPs analysis was conducted using an innovative Italian patented extraction methodology coupled with SEM-EDX detection. Our findings reveal the presence of MPs in all collected sponge specimens, indicating a pollution rate of 100%. The abundance of MPs in the four sponge species ranged from 3.95×105 to 1.05×106 particles per gram dry weight of sponge tissue, with significant differences observed among sampling sites but no species-specific differences. These results imply that the uptake of MPs by sponges is likely influenced by aquatic environmental pollution rather than the sponge species themselves. The smallest and largest MPs were identified in C. reniformis and P. ficiformis, with median diameters of 1.84 μm and 2.57 μm, respectively. Overall, this study provides the first evidence and an important baseline for the ingestion of small MP particles in Mediterranean sponges, introducing the hypothesis that they may serve as valuable bioindicators of MP pollution in the near future.

Insight into the environmental fate, hazard, detection, and sustainable degradation technologies of chlorpyrifos-an organophosphorus pesticide

Pesticides play a critical role in terms of agricultural output nowadays. On top of that, pesticides provide economic support to our farmers. However, the usage of pesticides has created a public health issue and environmental hazard. Chlorpyrifos (CPY), an organophosphate pesticide, is extensively applied as an insecticide, acaricide, and termiticide against pests in various applications. Environmental pollution has occurred because of the widespread usage of CPY, harming several ecosystems, including soil, sediment, water, air, and biogeochemical cycles. While residual levels in soil, water, vegetables, foodstuffs, and human fluids have been discovered, CPY has also been found in the sediment, soil, and water. The irrefutable pieces of evidence indicate that CPY exposure inhibits the choline esterase enzyme, which impairs the ability of the body to use choline. As a result, neurological, immunological, and psychological consequences are seen in people and the natural environment. Several research studies have been conducted worldwide to identify and develop CPY remediation approaches and its derivatives from the environment. Currently, many detoxification methods are available for pesticides, such as CPY. However, recent research has shown that the breakdown of CPY using bacteria is the most proficient, cost-effective, and sustainable. This current article aims to outline relevant research events, summarize the possible breakdown of CPY into various compounds, and discuss analytical summaries of current research findings on bacterial degradation of CPY and the potential degradation mechanism.

Long-term nitrogen fertilizer management for enhancing use efficiency and sustainable cotton (Gossypium hirsutum L.)

Optimal management of nitrogen fertilizer profoundly impacts sustainable development by influencing nitrogen use efficiency (NUE) and seed cotton yield. However, the effect of long-term gradient nitrogen application on the sandy loam soil is unclear. Therefore, we conducted an 8-year field study (2014-2021) using six nitrogen levels: 0 kg/hm2 (N0), 75 kg/hm2 (N1), 150 kg/hm2 (N2), 225 kg/hm2 (N3), 300 kg/hm2 (N4), and 375 kg/hm2 (N5). The experiment showed that 1) Although nitrogen application had insignificantly affected basic soil fertility, the soil total nitrogen (STN) content had decreased by 5.71%-19.67%, 6.67%-16.98%, and 13.64%-21.74% at 0-cm-20-cm, 20-cm-40-cm, and 40-cm-60-cm soil layers, respectively. 2) The reproductive organs of N3 plants showed the highest nitrogen accumulation and dry matter accumulation in both years. Increasing the nitrogen application rate gradually decreased the dry matter allocation ratio to the reproductive organs. 3) The boll number per unit area of N3 was the largest among all treatments in both years. On sandy loam, the most optional nitrogen rate was 190 kg/hm2-270 kg/hm2 for high seed cotton yield with minimal nitrogen loss and reduced soil environment pollution.

Solar light driven enhanced photocatalytic treatment of azo dye contaminated water based on Co-doped ZnO/ g-C3N4 nanocomposite

The current research concentrated on the Co-precipitation synthesis of g-C3N4 (CN), ZnO, ZnO/CN, and Co-doped ZnO/CN nanocomposite, as well as the solar light enhanced photocatalytic treatment of Reactive Red 120 (RR120) from genuine wool textile effluent. The 3D flower-like structure of Co-doped ZnO distributed on the surface of CN thin sheets, according to structural studies employing XRD and SEM examinations Electrochemical experiments exhibited that the Co-doped ZnO/CN nanocomposite has a large electroactive surface area. The optical band-gap values of CN, ZnO, ZnO/CN, and Co-doped ZnO/CN nanocomposites were 2.68, 3.13, 2.38, and 2.23 eV, respectively, according to optical characterizations. The synergistic effects and heterojunction produced by Co-doped ZnO and CN can be linked to the narrow gap in nanocomposites. After 75, 60, 50, and 40 min of exposure to solar light, photocatalytic degradation assays for 250 mL of 20 mg/L RR120 solution in the presence of CN, ZnO, ZnO/CN, and Co-doped ZnO/CN nanocomposites demonstrated 100% dye treatment. The applicability of photocatalysts for decolorization of 250 mL of 10 mg/L RR120 prepared from actual wool textile wastewater was investigated, and the results showed that Co-doped ZnO/CN nanocomposites for treatment of RR120 from actual wool textile wastewater were highly efficient at photocatalytic degradation.

Unravelling the molecular and biochemical responses in cotton plants to biochar and biofertilizer amendments for Pb toxicity mitigation

Over the past few years, there has been a rising interest in employing biochar (BC) and biofertilizers (BF) as a means of restoring soils that have been polluted by heavy metals. The primary objective of this study was to examine how the application of BC and BF affects the ability of cotton plants to withstand Pb toxicity at varying concentrations (0, 500, and 1000 mg/kg soil). The findings revealed that exposure to Pb stress, particularly at the 1000 mg/kg level, led to a decline in the growth and biomass of cotton plants. Pb toxicity triggered oxidative damage, impaired the photosynthetic apparatus, and diminished the levels of photosynthetic pigments. By increasing the expression of Rubisco-S, Rubisco-L, P5CR, and PRP5 genes and regulating proline metabolism, BC and BF increased the levels of proline and photosynthetic pigments and protected the photosynthetic apparatus. The application of BC and BF resulted in an upregulation of genes such as CuZnSOD, FeSOD, and APX1, as well as an increase in the activity of the glyoxalase system and antioxidant enzymes. These changes enhanced the antioxidant capacity of the plants and provided protection to membrane lipids from oxidative stress caused by Pb. The inclusion of BC and BF offered protection to photosynthesis and other essential intracellular processes in leaves by minimizing the transfer of Pb to leaves and promoting the accumulation of thiol compounds. This protective effect helped mitigate the negative impact of the toxic metal Pb on leaf function. By improving plant tolerance, reducing metal transfer, strengthening the antioxidant defense system, and enhancing the level of protective substances, these amendments show promise as valuable tools in tackling heavy metal pollution.

Production and Characterization of a Novel Symbiotic Plant-based Beverage Rich in Antioxidant Phenolic: Mung Bean and Rye Sprouts

There is an increasing demand for non-dairy probiotic food due to the constraints associated with dairy probiotics. In this study, a co-culture synbiotic beverage was prepared using a mixture of mung bean and rye sprouts inoculated with Lactobacillus plantarum (B-28) and Lactobacillus casei (B-29), along with inulin and oligofructose as prebiotics. The effects of prebiotic addition and starter culture on the survival of probiotics during cold storage and simulated gastric conditions were examined. Additionally, titratable acidity, pH, phenolic content, antioxidant activity, and sensory characteristics were evaluated over a 28-day period. The resulting product demonstrated good survival for L. casei (107 CFU.ml-1) and L. plantarum (106 CFU.ml-1) after 4 weeks under refrigeration with no significant changes in quality. The samples exhibited significantly high total phenolic content (TPC), ranging from 19.18 to 25.75 mg GAE/100 mL, which L. casei-containing drinks exhibited the highest TPC activity (p < 0.05). All treatments showed a significant reduction in probiotic survival during gastrointestinal digestion in the laboratory conditions (p < 0.05), although more than 50% survival was observed for all strains. The addition of prebiotics to the beverages led to a significant decrease in phenolic content (p < 0.05), but improved sensory scores. The highest turbidity was observed in the sample containing both probiotics and inulin on the 28th day at 38.1 (NTU). In general, the synergistic effect of probiotics was more pronounced when used together with both prebiotics in the beverages compared to their individual use. The results suggest that the production of this beverage could serve as a nutritious alternative to lactose-sensitive dairy beverages and contribute to the development of future probiotic food products.

Woody and herbaceous wastes for the remediation of polluted waters of wetlands

Plants wastes play an important role during water remediation in wetlands. Plant waste is made into biochar, which is usually used directly or as a water biofilter to remove pollutants. While, the water remediation effect of combination for biochar from woody and herbaceous wastes coupling with substrate types in CWs have not been fully explored. To explore the water remediation effect of combination for biochar coupling with substrate on pH, Turbidity, COD, NH₄⁺-N, TN and TP, four plant configuration modes combining seven woody plants and eight herbaceous plants (Plants A, Plants B, Plants C, Plants D) were coupled with three substrate types (Substrate 1, Substrate 2, Substrate 3) as 12 experiment groups, using water detection methods and significant differences test (LSD) to analyze. Results showed: (1) Compared to Substrate 3, Substrate 1 and Substrate 2 removed significantly higher in pollutants concentration (p < 0.05); (2) NH₄⁺-N final concentration in Plants C and Plants D were both significantly lower than Plants A and Plants B coupling with Substrate 1 and Substrate 2 (p < 0.05). The TN final concentration of Plants C was significantly lower than Plants A in Substrate 1 (p < 0.05), and Plants A's turbidity was significantly lower than Plants C and Plants D's in Substrate 2 (p < 0.05); (3) The pollutants removal of group A1, A2, B1, B2, C1, C2, D1 and D2 were significantly higher than other experiment groups (p < 0.05). Group A2, B2, C1 and D1 had the best water remediation effect and better stability of plant community. Findings in this study will be beneficial for remediating polluted water and building sustainable wetlands.

Growth Optimization and Rearing of Mealworm (Tenebrio molitor L.) as a Sustainable Food Source

As a sustainable food source for humans, mealworms (Tenebrio molitor) have a great deal of potential, due to the fact that they have a very favorable nutritional profile and a low environmental impact. For meal production, feed formulation and optimization are important. The mealworm Tenebrio molitor (Coleoptera: Tenebrionidae) is the most consumed insect in the world. Mealworms were given a variety of diets, including wheat bran as constant diet supplemented with different levels of Ospor (Bacillus clausii) at 0.002 g, 0.004 g, 0.006 g, and 0.008 g; imutec (Lacticaseibacillus rhamnosus) at 0.2 g. 0.4 g, 0.6 g, and 0.8 g; fungi (Calocybe indica) at 250 g, 500 g, and 750 g; yeast (Saccharomyces cerevisiae) at 50 g, 100 g, and 150 g; and wheat bran (standard diet) were examined in complete randomized design (CRD). Different parameters, i.e., the larval, pupal, and adult weight, size, life span, and nutritional profile of mealworm were studied. When compared with other insect growth promoters, only wheat bran was discovered to be the most efficient. It generated the heaviest and longest larvae at 65.03 mg and 18.32 mm, respectively, as well as pupae weighing 107.55 mg and 19.94 mm, respectively, and adults weighing 87.52 mg and 20.26 mm, respectively. It was also determined that fungi (C. indica) and ospor (B. clausii) promoted faster larval development than yeast (S. cerevisiae) and imutec (L. rhamnosus). Larval mortality was also greater in the imutec (L. rhamnosus) and yeast (S. cerevisiae) diets than the others. No pupal mortality was recorded in all diets. Furthermore, the protein content of Tenebrio. molitor raised on a diet including fungi (C. indica) was the highest at (375 g), with a content of 68.31%, followed by a concentration of (250 g) with a content of 67.84%, and wheat bran (1 kg) (normal diet) with the lowest content at 58.91%. T. molitor larvae fed a diet supplemented with bacterial and fungal had lower fat and ash content than bran-fed T. molitor larvae (standard diet). Wheat bran (normal diet) had the highest fat at 16.11%, and ash at 7.71%. Hence, it is concluded that wheat bran alone or diet containing fungi (C. indica) and ospor (B. clausii) performed better in terms of growth, and these diets and protein content are recommended for the mass rearing of mealworms.