Volatile Fatty Acid Production from Food Waste Leachate Using Enriched Bacterial Culture and Soil Bacteria as Co-Digester

Abstract

The production of volatile fatty acids (VFAs) from waste stream has been recently getting attention as a cost-effective and environmentally friendly approach in mechanical–biological treatment plants. This is the first study to explore the use of a functional bacterium, AM5 isolated from forest soil, which is capable of enhancing the production of VFAs in the presence of soil bacteria as a co-digester in non-strict anaerobic fermentation processes of food waste leachates. Batch laboratory-scale trials were conducted under thermophilic conditions at 55 °C and different pH values ranging from approximately 5 to 11, as well as under uncontrolled pH for 15 days. Total solid content (TS) and volatile solid content (VS) were observed with 58.42% and 65.17% removal, respectively. An effluent with a VFA concentration of up to 33,849 mg/L (2365.57 mg/g VS; 2244.45 mg/g chemical oxygen demand (COD)-VFA VS; 1249 mg/g VSremoved) was obtained at pH 10.5 on the second day of the batch culture. The pH resulted in a significant effect on VFA concentration and composition at various values. Additionally, all types of VFAs were produced under pH no-adjustment (approximately 5) and at pH 10.5. This research might lead to interesting questions and ideas for further studies on the complex metabolic pathways of microbial communities in the mixture of a soil solution and food waste leachate.

Biodegradation of Methylene Blue Using a Novel Lignin Peroxidase Enzyme Producing Bacteria, Named Bacillus sp. React3, as a Promising Candidate for Dye-Contaminated Wastewater Treatment

“…Molecular identification was performed using 16S rRNA gene sequencing. The 27F and 1492R universal primers were used to amplify the 16S rRNA gene, and sequencing was performed with Macrogen using 785F and 907R primers [25]. The PCR products were purified using a multiscreen filter plate (Millipore Corp., Bedford, MA, USA) and were then sequenced using 518F (50-CCAGCAGCCGCGGTAATACG-30) and 800R (50-TACCAGGGTATCTAATCC-30) primers with the PRISM BigDye Terminator v3.1 Cycle Sequencing Kit (Applied Biosystems, Foster City, CA, USA).…”

Purification and Characterization of Strong Simultaneous Enzyme Production of Protease and α-Amylase from an Extremophile-Bacillus sp. FW2 and Its Possibility in Food Waste Degradation

“…These samples were incubated at different temperatures of −6 • C, 10 C on a rotary shaker at 200 rpm (1 d interval for each temperature change). The surviving bacterial culture in the medium (1 mL) was transferred to a fresh medium prepared as above and incubated at 30 • C for 5 d. Well-separated colonies were sub-cultured to obtain pure cultures, and they were subsequently examined for enzyme production and waste degradation ability in the subsequent steps [18,19,27].…”

“…Besides proteases, amylases are also industrial enzymes that are applied in food fermentation, paper, textile, and biofuel industries [12,13]. There are various genera that produce amylase, including Bacillus, Micrococcus, Streptomyces, Pseudomonas, and Arthrobacter [14][15][16][17][18][19]. Bacillus genus is well known and famous for α-amylase production.…”

Improvement of Hydrogen Production during Anaerobic Fermentation of Food Waste Leachate by Enriched Bacterial Culture Using Biochar as an Additive

“…The medium used in this study was the same as that described in previous studies with the following composition (per 1 L): glucose 10 g, beef extract 2 g, peptone 4 g, yeast extract 1 g, NaCl 2 5 g, K 2 HPO 4 1.5 g, MgCl 2 •6H 2 O 0.6 g, FeSO 4 •7H 2 O 0.2 g, L-cysteine 0.5 g, trace elements 10 mL, and vitamin solution 10 mL. The vitamin solution contained the following (per 1 L): riboflavin 0.025 g, citric acid 0.02 g, folic acid 0.01 g, and para-aminobenzoic acid 0.01 g. The trace element solution was composed of the following (per 1 L): MnSO O 0.2 g, and AlK(SO 4 ) 2 0.01 g [4,29]. The vitamin solution was added after autoclaving the medium and trace elements as the last step.…”

“…Food waste leachate (FWL) is a major secondary wastewater pollutant generated by FW during the decomposition process; however, studies on bioenergy production from FWL have been limited. This wastewater is preferentially treated by anaerobic fermentation (AF), due to its high biodegradability and moisture content, to produce important products, such as volatile fatty acids (VFAs) and hydrogen [3,4]. Although advances in AF technologies have been made to better utilize the capacity of resource conversion from FWL, the field continues to face numerous limitations, such as reaction Microorganisms 2021, 9, 2438 2 of 12 rates and substrate mass transfer during AF.…”