Halophilic bacteria mediated poly-β-hydroxybutyrate production using paddy straw as a substrate

Naitam, Mayur G.; Tomar, Govind Singh; Pushpad, Udita; Singh, Surender; Kaushik, Rajeev

doi:10.1016/j.biteb.2021.100915

Cited by 3 publications

(3 citation statements)

References 52 publications

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“…Sugars released during saccharification were used as a carbon source @ 2% based on the sugar content in saccharified products and bacteria were grown on the medium formulated by adding other components of Reese mineral medium. The carbon to nitrogen ratio was adjusted to 30:1 and 38:1 for B. cereus LB7 and B. gladioli 2S4R1, respectively [ 38 ] for the optimum requirement using ammonium sulfate and incubated at 30 °C for 72 h. The minimal media for growing PHB producing isolates were modified by replacing glucose with saccharified leachate and was designated as minimal media with saccharified leachate (MMSL). In case the amount of saccharified sugars is less than 2% in leachate then glucose will be used as a preferred carbon source for supplementing MMSL.…”

Section: Methodsmentioning

confidence: 99%

“…Bacterial isolates were grown in MMSL for PHB production and compared with PHB production using standard minimal medium (MM) having laboratory grade glucose as carbon source in triplicates. Based on the growth kinetics studies [ 38 ] isolates were incubated at 30 °C for 72 h. PHB from the bacterial biomass was extracted as per the method described by Hahn et al [ 46 ]. Extracted PHB was quantified using HPLC and spectrophotometer as described by Karr et al [ 47 ].…”

Section: Methodsmentioning

confidence: 99%

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Optimization and production of holocellulosic enzyme cocktail from fungi Aspergillus nidulans under solid-state fermentation for the production of poly(3-hydroxybutyrate)

Naitam

Tomar

Kaushik

2022

Fungal Biol Biotechnol

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The production of petroleum-based plastics increased dramatically following industrialization. Because of multifaceted properties such as durability, thermostability, water resistance, and many others, these plastics have become an indispensable part of daily life. However, while improving people’s quality of life, indiscriminate use of plastics has caused pollution and raised environmental concerns. To address this situation and reduce environmental risks, microbially produced biopolymers such as poly-3-hydroxyalkanoates can be used to make bioplastics that are completely biodegradable under normal environmental conditions. At the moment, the cost of bioplastic production is high when compared to petroleum-based plastics, so alternate strategies for making the bioplastic process economical are urgently needed. Agricultural waste is abundant around the world and can be efficiently used as a low-cost renewable feedstock after pretreatment and enzymatic hydrolysis. Fungi are well known as primary degraders of lignocellulosic waste, and this property was used in the current study to enzymatically hydrolyze the pretreated paddy straw for the production of reducing sugars, which were then used in the microbial fermentation for the production of PHB. In this study, Aspergillus nidulans was used to advance a low-cost and efficient enzyme hydrolysis system for the generation of reducing sugars from lignocellulosic biomass. For the production of the holocellulosic enzyme complex, the fungus was grown on wheat straw with Reese mineral medium as a wetting agent. After 216 h of solid-state fermentation at 30 °C, pH 6.0, the enzyme extract from A. nidulans demonstrated the highest activity, CMCase 68.58 (± 0.55), FPase 12.0 (± 0.06), Xylanase 27.17 (± 0.83), and β-glucosidase 1.89 (± 0.037). The initial pH, incubation temperature, and time all had a significant impact on final enzyme activity. Enzymatic hydrolysis of pretreated paddy straw produced reducing sugars (8.484 to 30.91 gL−1) that were then used to produce poly(3-hydroxybutyrate) using halophilic bacterial isolates. Burkholderia gladioli 2S4R1 and Bacillus cereus LB7 accumulated 26.80% and 20.47% PHB of the cell dry weight, respectively. This suggests that the holocellulosic enzyme cocktail could play a role in the enzymatic hydrolysis of lignocellulosic materials and the production of PHA from less expensive feedstocks such as agricultural waste.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Optimization and production of holocellulosic enzyme cocktail from fungi Aspergillus nidulans under solid-state fermentation for the production of poly(3-hydroxybutyrate)

Naitam

Tomar

Kaushik

2022

Fungal Biol Biotechnol

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“…Two halophilic bacteria, Bacillus cereus LB7 and Burkholderia gladioli 2S4R1, were recently found to use mixed sugars obtained from paddy straw hydrolysis. Under optimal C:N ratios of 30:1 and 38:1 and unique growth media, PHB productivities of 0.39 g/L/h and 0.31 g/L/h, respectively [47], were achieved. This work is a unique demonstration showing bioconversion of paddy straw hydrolysate by halophilic bacteria that must be explored further for industrial-scale applications.…”

Section: Other Waste Materials As Substratementioning

confidence: 99%

Recent Challenges and Trends of Polyhydroxyalkanoate Production by Extremophilic Bacteria Using Renewable Feedstocks

Możejko-Ciesielska,

Ray,

Sankhyan

2023

Polymers

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Polyhydroxyalkanoates (PHAs) are biodegradable polymers with immense potential in addressing the global plastic pollution crisis and advancing sustainable bioplastics production. Among the various microbes known for PHA production, extremophilic bacteria possess unique capabilities to thrive under extreme conditions, making them attractive candidates for PHA synthesis. Furthermore, the utilization of renewable feedstocks for PHA production aligns with the growing demand for sustainable bioplastic alternatives. A diverse range of extremophilic bacteria, especially halophiles and thermophiles, has provided cost-competitive platforms for producing customized PHA polymers. Extremophilic bacteria offer unique advantages over mesophiles due to their contamination resistance, high cell density growth, and unique culture conditions. The current status of Halomonas spp. as a chassis further allows exploration of metabolic engineering approaches to overcome the challenges associated with current industrial biotechnology. This article especially focuses on extremophilic bacteria and explores recent advances in utilizing renewable feedstocks such as lignocellulosic biomass, agro-industrial residues, and waste streams for PHA production. The integration of biorefinery concepts and circular economy principles in PHA manufacturing is also examined. This review is an attempt to provide an understanding of renewable substrates as feedstocks and emerging trends in PHA production by extremophilic bacteria. It underscores the pivotal role of extremophiles and sustainable feedstock sources in advancing the feasibility and eco-friendliness of PHAs as a promising biopolymer alternative.

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Optimization of Production of Polyhydroxyalkanoates (PHAs) from Newly Isolated Ensifer sp. Strain HD34 by Response Surface Methodology

2022

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Petroleum-based plastics have become a big problem in many countries because of their non-degradability and that they become microplastics in the environment. This study focused on the optimization of production medium and conditions of polyhydroxyalkanoates (PHAs), which are biodegradable bioplastics and are accumulated in microbial cells. Among 341 isolates from 40 composted soil samples, the best isolate was the HD34 strain, which was identified using morphological, molecular, and biochemical methods. The results showed that the strain was most closely related to Ensifer adhaerens LMG20216T, with 99.6% similarity. For optimization of production medium and conditions using response surface methodology, it exhibited an optimal medium containing 3.99% (w/v) of potato dextrose broth (PDB) and 1.54% (w/v) of D-glucose with an adjusted initial pH of 9.0. The optimum production was achieved under culture conditions of a temperature of 28 °C, inoculum size of 2.5% (v/v), and a shaking speed of 130 rpm for 5 days. The results showed the highest PHA content, total cell dry weight, and PHA yield as 72.96% (w/w) of cell dry weight, 9.30 g/L, and 6.78 g/L, respectively. The extracted PHA characterization was studied using gas chromatography, 1H NMR, FTIR, and XRD. The results found that the polymer was a polyhydroxybutyrate (PHB) with a melting temperature (Tm) and degradation temperature (Td) of 173.5 °C and 260.8 °C, respectively.

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Halophilic bacteria mediated poly-β-hydroxybutyrate production using paddy straw as a substrate

Cited by 3 publications

References 52 publications

Optimization and production of holocellulosic enzyme cocktail from fungi Aspergillus nidulans under solid-state fermentation for the production of poly(3-hydroxybutyrate)

Optimization and production of holocellulosic enzyme cocktail from fungi Aspergillus nidulans under solid-state fermentation for the production of poly(3-hydroxybutyrate)

Recent Challenges and Trends of Polyhydroxyalkanoate Production by Extremophilic Bacteria Using Renewable Feedstocks

Optimization of Production of Polyhydroxyalkanoates (PHAs) from Newly Isolated Ensifer sp. Strain HD34 by Response Surface Methodology

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