Production of poly-3-hydroxybutyrate (P3HB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) P(3HB-co-3HV) from synthetic wastewater using Hydrogenophaga palleronii

In the present study, synthetic wastewater (SW) was used for production of poly-3-hydroxybutyrate (P3HB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) P(3HB-co-3HV) using the bacteria Hydrogenophaga palleronii. SW at various volatile fatty acids concentrations (5–60 g/l) was evaluated for the growth and biopolymer production using H. palleronii. Substrate degradation was analyzed using total organic carbon (TOC) analyzer and high pressure liquid chromatography (HPLC). H. palleronii showed highest and lowest removal of TOC at 5 g/l (88 ± 4%) and 60 g/l (15 ± 6%) respectively. Among all the concentrations evaluated, bacteria showed highest biopolymer production with 20 g/l (63 ± 5%), followed by 30 g/l (58 ± 3%) and 40 g/l (56 ± 2%). Lowest biopolymer production was observed at 5 g/l concentration (21 ± 3%). Structure, molecular weight, and thermal properties of the produced biopolymer were analyzed. These results denoted that the strain H. palleronii can be used for degradation of high concentration of volatile fatty acids persistent in wastewaters and their subsequent conversion into useable biopolymers

Two-Stage Polyhydroxyalkanoates (PHA) Production from Cheese Whey Using Acetobacter pasteurianus C1 and Bacillus sp. CYR1

Cheese whey (CW) can be an excellent carbon source for polyhydroxyalkanoates (PHA)-producing bacteria. Most studies have used CW, which contains high amounts of lactose, however, there are no reports using raw CW, which has a relatively low amount of lactose. Therefore, in the present study, PHA production was evaluated in a two-stage process using the CW that contains low amounts of lactose. In first stage, the carbon source existing in CW was converted into acetic acid using the bacteria, Acetobacter pasteurianus C1, which was isolated from food waste. In the second stage, acetic acid produced in the first stage was converted into PHA using the bacteria, Bacillus sp. CYR-1. Under the condition of without the pretreatment of CW, acetic acid produced from CW was diluted at different folds and used for the production of PHA. Strain CYR-1 incubated with 10-fold diluted CW containing 5.7 g/L of acetic acid showed the higher PHA production (240.6 mg/L), whereas strain CYR-1 incubated with four-fold diluted CW containing 12.3 g/L of acetic acid showed 126 mg/L of PHA. After removing the excess protein present in CW, PHA production was further enhanced by 3.26 times (411 mg/L) at a four-fold dilution containing 11.3 g/L of acetic acid. Based on Fourier transform infrared spectroscopy (FT-IR), and H-1 and C-13 nuclear magnetic resonance (NMR) analyses, it was confirmed that the PHA produced from the two-stage process is poly-beta-hydroxybutyrate (PHB). All bands appearing in the FT-IR spectrum and the chemical shifts of NMR nearly matched with those of standard PHB. Based on these studies, we concluded that a two-stage process using Acetobacter pasteurianus C1 and Bacillus sp. CYR-1 would be applicable for the production of PHB using CW containing a low amount of lactose

Degradation of Toxic Compounds at Low and Medium Temperature Conditions Using Isolated Fungus

In the present study, a fungal strain isolated from the Antarctic soil was identified as Penicillium sp. CHY-2 based on its 5.8S rRNA gene sequence analysis. Furthermore, its biodegradation ability towards 13 different toxic compounds such as 4-butylphenol (4-BP), 4-sec-butylphenol (4-s-BP), 4-tert-butylphenol (4-t-BP), 4-nonylphenol (4-NP), 4-tert-octylphenol (4-t-OP), 4-chlorophenol (4-CP), phenol, bisphenol A (BPA), benzene, toluene, xylene, naphthalene, and phenanthrene at low (4°C) and medium (15°C) temperature conditions was evaluated using high pressure liquid chromatography. Among the 13 compounds, the strain CHY-2 effectively degraded the six compounds i.e., 4-BP, 4-s-BP, 4-t-BP, 4-NP, 4-CP, and phenol at 15°C within one week, and at 4°C within 3 weeks. Also CHY-2 effectively degraded the 4-t-OP at 15°C (70%), but not at 4°C (35%). Among different carbon sources tested, glucose was found to be the most suitable and the growth of CHY-2 at 4°C was slower than at 15°C. Addition of Tween 80 increased the growth and degradation ability of CHY-2 towards 4-BP at 4 and 15°C. The metabolites produced during the degradation of 4-BP were identified by gas chromatography-mass spectrometry. Also, bacteria present in the Antarctic soil were determined by denaturing gradient gel electrophoresis and the result showed the presence of Pseudomonas and Syntrophus groups of bacteria

Bioprocessing of Waste for Renewable Chemicals and Fuels to Promote Bioeconomy

The world’s rising energy needs, and the depletion of fossil resources demand a shift from fossil-based feedstocks to organic waste to develop a competitive, resource-efficient, and low-carbon sustainable economy in the long run. It is well known that the production of fuels and chemicals via chemical routes is advantageous because it is a well-established technology with low production costs. However, the use of toxic/environmentally harmful and expensive catalysts generates toxic intermediates, making the process unsustainable. Alternatively, utilization of renewable resources for bioprocessing with a multi-product approach that aligns novel integration improves resource utilization and contributes to the “green economy”. The present review discusses organic waste bioprocessing through the anaerobic fermentation (AF) process to produce biohydrogen (H2), biomethane (CH4), volatile fatty acids (VFAs) and medium chain fatty acids (MCFA). Furthermore, the roles of photosynthetic bacteria and microalgae for biofuel production are discussed. In addition, a roadmap to create a fermentative biorefinery approach in the framework of an AF-integrated bioprocessing format is deliberated, along with limitations and future scope. This novel bioprocessing approach significantly contributes to promoting the circular bioeconomy by launching complete carbon turnover practices in accordance with sustainable development goals

Degradation of Toxic Compounds at Low and Medium Temperature Conditions Using Isolated Fungus

application/pdfIn the present study, a fungal strain isolated from the Antarctic soil was identified as Penicillium sp. CHY-2 based on its 5.8S rRNA gene sequence analysis. Furthermore, its biodegradation ability towards 13 different toxic compounds such as 4-butylphenol (4-BP), 4-sec-butylphenol (4-s-BP), 4-tert-butylphenol (4-t-BP), 4-nonylphenol (4-NP), 4-tert-octylphenol (4-t-OP), 4-chlorophenol (4-CP), phenol, bisphenol A (BPA), benzene, toluene, xylene, naphthalene, and phenanthrene at low (4°C) and medium (15°C) temperature conditions was evaluated using high pressure liquid chromatography. Among the 13 compounds, the strain CHY-2 effectively degraded the six compounds i.e., 4-BP, 4-s-BP, 4-t-BP, 4-NP, 4-CP, and phenol at 15°C within one week, and at 4°C within 3 weeks. Also CHY-2 effectively degraded the 4-t-OP at 15°C (70%), but not at 4°C (35%). Among different carbon sources tested, glucose was found to be the most suitable and the growth of CHY-2 at 4°C was slower than at 15°C. Addition of Tween 80 increased the growth and degradation ability of CHY-2 towards 4-BP at 4 and 15°C. The metabolites produced during the degradation of 4-BP were identified by gas chromatography-mass spectrometry. Also, bacteria present in the Antarctic soil were determined by denaturing gradient gel electrophoresis and the result showed the presence of Pseudomonas and Syntrophus groups of bacteria