Bioprocess optimization of PHB homopolymer and copolymer P3 (HB-co-HV) byAcinetobacter juniiBP25 utilizing rice mill effluent as sustainable substrate

Abstract

The potential use of parboiled rice mill effluent as a cheap substrate for the production of homopolymer and copolymer of Polyhydroxyalkanoates (PHAs) by Acinetobacter junii BP 25 was investigated for the first time. Process optimization by one factor at a time led to homopolymer polyhydroxybutyrate (PHB) production of 2.64 ± 0.18 g/l with 94.28% PHB content using a two-stage batch cultivation mode. BP 25 furthermore produced polyhydroxybutyrate-co-hydroxyvalerate (P3 (HB-co-HV)), with the addition of valeric acid as an additive to the substrate, yielding (2.56 ± 0.12 g/l dry biomass, 2.20 ± 0.15 g/l PHA) a copolymer content of 85.93%. Thus, rice mill effluent can be an effective and relatively low-cost alternative for the production of PHA, replacing the pure substrates.

Bioprocess optimization of PHB production utilizing agro (sago) waste as a sustainable substrate by the native isolate, Bacillus cereus

“…In this study, PHB production media is formulated by adding sago waste, the major waste in Salem District, Tamil Nadu, India, as a carbon source in order to decrease the cost of production media since the raw materials used in production media are expensive. Sabapathy et al (2017) used rice mill as alternative substrate for the production of PHA and reported that about 2.2 g/l of PHA was produced from the optimized media. Likewise, pineapple peel also could be a better and an alternative cheapest carbon source for increasing the PHB yield (5.55 g/l) by B. drentensis strain BP17 under the statistically optimized condition (Penkhrue et al 2020).…”

Development of an Integrated Biorefinery System for Bioconversion of Lignocellulosic Biomass to Polyhydroxyalkanoates and Biohydrogen

“…Then, it was added to 4% sodium hypochlorite at room temperature for 1–2 h. The contents were spun at 5000 rpm for 15 min, and the pellet was washed with acetone: diethyl ether in 1:1 proportion twice to remove the cell debris. The obtained PHA was liquefied in hot chloroform and then subjected to evaporation for getting the polymer . The dry weight of the polymer was measured, and the PHA content was measured using the following equation normalP normalH normalA % = ( w e i g h t o f P H A / d r y c e l l w e i g h t ) × 100 …”

“…To determine the dry cell weight, the cell pellets were taken, washed with distilled water, and dried at 105 °C for 48 h until the constant weight was attained. Then, following the measurement of dry cell weight, the dried pellet was washed with acetone and ethanol 37 to remove the surface-bound impurities. Then, it was added to 4% sodium hypochlorite at room temperature for 1−2 h. The contents were spun at 5000 rpm for 15 min, and the pellet was washed with acetone: diethyl ether in 1:1 proportion twice to remove the cell debris.…”

“…The obtained PHA was liquefied in hot chloroform and then subjected to evaporation for getting the polymer. 37 The dry weight of the polymer was measured, and the PHA content was measured using the following equation = × PHA% (weight of PHA/dry cell weight) 100…”

A comparative analysis of perforation and blister features on internally corroded aged water pipeline wall

“…These bands indicate the presence of hydroxybutyrate polymer, and the results are in agreement with those reported elsewhere. [39][40][41] The peaks at 1628 and 1129 cm −1 corresponded to the amide functional groups II (N-H) and III (C-N), respectively, in the protein molecules, suggesting the presence of microorganisms.…”