Changes in the taxonomic and functional structure of microbial communities during vegetable waste mixed silage fermentation

Silage fermentation, a sustainable way to use vegetable waste resources, is a complex process driven by a variety of microorganisms. We used lettuce waste as the main raw material for silage, analyzed changes in the physico-chemical characteristics and bacterial community composition of silage over a 60-day fermentation, identified differentially abundant taxa, predicted the functional profiles of bacterial communities, and determined the associated effects on the quality of silage. The biggest changes occurred in the early stage of silage fermentation. Changes in the physico-chemical characteristics included a decrease in pH and increases in ammonia nitrogen to total nitrogen ratio and lactic acid content. The numbers of lactic acid bacteria (LAB) increased and molds, yeasts and aerobic bacteria decreased. The bacterial communities and their predicted functions on day 0 were clearly different from those on day 7 to day 60. The relative abundances of phylum Firmicutes and genus Lactobacillus increased. Nitrite ammonification and nitrate ammonification were more prevalent after day 0. The differences in the predicted functions were associated with differences in pH and amino acid, protein, carbohydrate, NH3-N, ether extract and crude ash contents.

Analysis of the use of media resulting from bioconversion of organic waste in the production of maggots BSF (black soldier fly)

Maggots is an organism derived from the eggs of the black fly, Hermentia illucens (black soldier fly, BSF), which undergoes metamorphosis in the second phase after the egg phase and before the pupa phase which then turns into an adult fly. The purpose of this study was to analyze the utilization of organic waste substrate on the production of BSF maggots cultivation. This research was conducted outdoor at the Freshwater Aquaculture Fisheries Center (BPBAT) Sungai Gelam Jambi with a completely randomized design (CRD) with 4 treatments and 3 replications; Treatment A: PKM (palm kernel meal) 100%, B (PKM 50% + cabbage vegetable waste 50%), C (PKM 50% + coconut pulp 50%) and D (PKM 50% + coconut pulp 25% + vegetable waste cabbage 25%). The average yield parameter of high maggots biomass in treatment A was 673.67 g/4 kg substrate and the lowest biomass in treatment D was 239.67 g/4 kg substrate. For the average weight and length of the best maggots in treatment A (0.20 g/individual) and (1.83 cm), the lowest was in B (0.12 g/Ind. and 1.58 cm). The highest was in treatment B (5,182.31 individual/4 kg substrate) and the lowest was in D (1,479.44 ind./4 kg substrate. The highest bioconversion value of maggots to organic matter OSE (organic substrate efficiency) was highest in treatment A (16, 84%) and the lowest was in D (5.99%). Technically, treatment A was slightly better than B, while economically the best organic substrate medium for maggots cultivation was in treatment B with a production cost of Rp. 7.257 and the ECR (economic conversion ratio) value of 5.81 was lower than the other 3 treatments. Keywords: Maggots, black soldier fly, Hermentia illucens, organic waste. ABSTRAK Maggots merupakan organisme yang berasal dari telur seranga lalat hitam, Hermentia illucens (black soldier fly, BSF). Tujuan penelitian ini yaitu menganalisis pemanfaatan subtrat limbah organik terhadap produksi budidaya maggots BSF. Penelitian ini dilaksanakan di Balai Perikanan Budidaya Air Tawar (BPBAT) Sungai Gelam, Jambi dengan rancangan acak lengkap (RAL) 4 perlakuan 3 ulangan yaitu perlakuan A : PKM (palm kernel meal) 100%, B (PKM 50% + limbah sayur kol 50%), C (PKM 50% + ampas kelapa 50%), dan D (PKM 50% + ampas kelapa 25%+ limbah sayur kol 25%).Rata-rata biomassa tertinggi didapatkan pada perlakuanA (673,67g/4 kg subtrat) dan biomassa terendah dihasilkan pada perlakuan D (239.67g/4 kg subtrat). Untuk bobot rata-rata dan panjang maggots terbaik dihasilkan pada perlakuan A (0,20 g/individu dan 1,83 cm/individu), terendah pada B (0,12 g/individu dan (1,58 cm). Jumlah populasi maggots yang terbanyak dihasilkan pada perlakuan B (5.182,31 ind./4 kg subtrat) dan terendah pada D (1.479,44 individu/4 kg subtrat). Nilai biokonversi maggots terhadap bahan organik OSEterbaik (organic substrate efficiency) tertinggi pada perlakuan A (16,84%) dan terendah pada D (5,99%). Secara teknis perlakuan A sedikit lebih baik dari B sedangkan secara ekonomi media subtrat organik terbaik untuk budidaya maggots terdapat pada perlakuan B dengan biaya produksi sebesar Rp. 7.257 dan nilai ECR (economic convertion ratio) sebesar 5.81 lebih rendah dari ke 3 perlakuan lainnya. Kata kunci: Maggots, black soldier fly, Hermentia illucens, limbah organik.

Anaerobic co-digestion of swine manure and forage at two harvesting ages

ABSTRACT: The co-digestion of swine manure with vegetable waste is an alternative that can increase the production of biogas and methane generated by the isolated digestion of manure. However, recommendations that are based on the best ratio between manure and forage, as well as the age of harvest, are still scarce in the literature. This study was conducted to evaluate inclusions (0, 25, 50, 75 and 100%) of the total solids (TS) of Elephant grass (Pennisetum purpureum Schum) harvested at two ages medium age (MA) at 45 days of growth and advanced age (AA) at 90 days in co-digestion with swine manure, using an entirely randomized design in a 5x2 factorial scheme. Batch digesters were used and biogas production was monitored for 12 weeks. There was influence of forage age (P <0.05) on the degradation of solids and neutral detergent fiber, with higher values for the substrates containing MA forage. The highest CH4 yields were obtained by the substrates containing MA forage in the inclusion of 27.7 and 31.6%, being 253.7 and 222.2 L of CH4 per Kg of total or volatile solids. The age of the forages influenced the onset and persistence of biogas production, being advantageous only in the inclusion of 25% of MA forage. The AA forage inclusion is not recommended for co-digestion with swine manure.

Compost Based on Pulp and Paper Mill Sludge, Fruit-Vegetable Waste, Mushroom Spent Substrate and Rye Straw Improves Yield and Nutritional Value of Tomato

Plant biomass in the form of waste materials and by-products from various industries can be a valuable material for the production of composts and growing media for urban gardening. In this study, pulp and paper mill sludge, fruit-vegetable waste, mushroom spent substrate and rye straw were used to produce compost that was further used as a medium component in container cultivation of tomato. The plants were grown in containers with a capacity of 3 dm3 filled with three types of compost-based growing media supplemented with high peat, fen peat, pine bark and wood fiber. The tomato plants grown in 100% peat substrate served as controls. The plants grown in the compost-enriched media had a higher leaf greening index and percentage of ripe fruit, and exhibited an increased content of total polyphenols and flavonoids, potassium, calcium, magnesium and copper in fruit as compared with the control. The tomatoes grown in a medium consisting of 25% compost, 30% high peat, 15% low peat, 20% pine bark and 10% wood fiber reached the highest fresh fruit weight, total polyphenol content and L-ascorbic acid levels. This study demonstrated that the compost produced from natural materials from various sources was a valuable potting medium supplement with positive effects on tomato yield and nutritional value.

Assessment of Waste Scavenging Activities in Calabar, Cross River State, Nigeria

The study was focus on assessing waste scavenging activities in Calabar, Cross River State. Specifically, the study appraised the socioeconomic characteristics of solid waste scavengers in Calabar and analysed the contributions of scavengers in the waste management process. The study obtained data through questionnaire administration. A total of 50 copies of questionnaire were distributed purposively to waste scavengers in the study area while descriptive statistics was used in carrying out analysis. It was observed that scavenging is exclusively carried out by males and those between 31 years and 40 years dominate the waste scavenging process. It was equally revealed that the married form a larger percent of scavengers in the study area. Scavengers were observed to be engaged in picking up irons/metals, plastics, glasses, copper, bottles as well as vegetables and food remains. Scavengers are mainly involved in the exercise in order to enable them earn a living. Therefore, wastes materials that are pickup in the process are sold out to recycling companies. Specifically, iron scraps pickers sell them to iron recycling companies while vegetable waste pickers sell to fertilizer production companies. Very few scavengers use the wastes they pick up for personal uses. However, it was noted that scavengers contribute positively in the management of solid waste in Calabar. Based on the findings, it was suggested that waste sorting should be encouraged among youths through the organization of sensitization campaigns and the awareness since it has the potentials of reducing unemployment while promoting waste management. Equally, scavengers should be recognized by the government as managers in the waste sector and be given some incentives

The Garbage Enzyme with Chinese Hoenylocust Fruits Showed Better Properties and Application than When Using the Garbage Enzyme Alone

Garbage enzyme (GE) is a vinegar or alcohol product derived from fermenting fresh kitchen waste, such as vegetable and fruit residues (peels, cuttings and bits), sugar (brown sugar, jaggery or molasses sugar) and water. Chinese honeylocust fruits (Gleditsia sinensis) have been used in China for at least 2000 years as a detergent. The aim of the study was to investigate the properties and application of Chinese honeylocust garbage enzyme (CHGE), which is produced when equal amounts of Chinese honeylocust fruits and fresh wastes are mixed. The results showed that CHGE had lesser microbial communities and lower surface tension than GE. CHGE also had higher viscosity, foam stability and emulsion stability than GE. Compared with GE, CHGE induced higher enzymatic amylase, cellulase, lipase and protease activities. CHGE had stronger detergency than GE and a 100× dilution of CHGE could significantly remove pesticide residues after a 30 min soaking treatment. The study showed that as a biological detergent, CHGE is safer and more environmentally friendly than GE and has remarkable washing and cleaning power. The preparation method of the detergent is simple: it can be prepared at home using fruit and vegetable waste, which is beneficial to the secondary utilization of waste and the reduction of pollution to the environment and damage to human health.