Bioprocess for co-production of polyhydroxybutyrate and violacein using Himalayan bacterium Iodobacter sp. PCH194

Kumar, Vijay; Darnal, Sanyukta; Kumar, Subhash; Kumar, Sanjay; Singh, Dharam

doi:10.1016/j.biortech.2020.124235

Cited by 35 publications

(29 citation statements)

References 45 publications

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“…Polyhydroxyalkanoates (PHAs), degradable polyesters of microbial origin, are promising “green” plastics, which are degraded by natural microflora to CO 2 and H 2 O, causing no harm to biota and the entire environment [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. PHAs are synthesized by prokaryotes from various substrates, including waste products [ 18 , 19 , 20 , 21 ]. Development of PHAs was a notable event for biotechnology of degradable materials [ 6 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ].…”

Section: Introductionmentioning

confidence: 99%

Laser Processing of Polymer Films Fabricated from PHAs Differing in Their Monomer Composition

et al. 2021

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The study reports results of using a CO2-laser in continuous wave (3 W; 2 m/s) and quasi-pulsed (13.5 W; 1 m/s) modes to treat films prepared by solvent casting technique from four types of polyhydroxyalkanoates (PHAs), namely poly-3-hydroxybutyrate and three copolymers of 3-hydroxybutyrate: with 4-hydroxybutyrate, 3-hydroxyvalerate, and 3-hydroxyhexanoate (each second monomer constituting about 30 mol.%). The PHAs differed in their thermal and molecular weight properties and degree of crystallinity. Pristine films differed in porosity, hydrophilicity, and roughness parameters. The two modes of laser treatment altered these parameters and biocompatibility in diverse ways. Films of P(3HB) had water contact angle and surface energy of 92° and 30.8 mN/m, respectively, and average roughness of 144 nm. The water contact angle of copolymer films decreased to 80–56° and surface energy and roughness increased to 41–57 mN/m and 172–290 nm, respectively. Treatment in either mode resulted in different modifications of the films, depending on their composition and irradiation mode. Laser-treated P(3HB) films exhibited a decrease in water contact angle, which was more considerable after the treatment in the quasi-pulsed mode. Roughness parameters were changed by the treatment in both modes. Continuous wave line-by-line irradiation caused formation of sintered grooves on the film surface, which exhibited some change in water contact angle (76–80°) and reduced roughness parameters (to 40–45 mN/m) for most films. Treatment in the quasi-pulsed raster mode resulted in the formation of pits with no pronounced sintered regions on the film surface, a more considerably decreased water contact angle (to 67–76°), and increased roughness of most specimens. Colorimetric assay for assessing cell metabolic activity (MTT) in NIH 3T3 mouse fibroblast culture showed that the number of fibroblasts on the films treated in the continuous wave mode was somewhat lower; treatment in quasi-pulsed radiation mode caused an increase in the number of viable cells by a factor of 1.26 to 1.76, depending on PHA composition. This is an important result, offering an opportunity of targeted surface modification of PHA products aimed at preventing or facilitating cell attachment.

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Section: Introductionmentioning

confidence: 99%

Laser Processing of Polymer Films Fabricated from PHAs Differing in Their Monomer Composition

et al. 2021

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“…And 11.0 g/L polyhydroxybutyrate and 1.5 g/L violacein pigment were successfully co-synthesized in Iodobacter sp. PCH194 ( Kumar et al, 2021 ). 7,12-dioxolithocholate and L- tert -leucine were simultaneously produced in a cofactor self-sufficient cascade system for enhancing the atom efficiency ( You et al, 2021 ).…”

Section: Resultsmentioning

confidence: 99%

Coproduction of 5-Aminovalerate and δ-Valerolactam for the Synthesis of Nylon 5 From L-Lysine in Escherichia coli

Cheng

Luo

et al. 2021

Front. Bioeng. Biotechnol.

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The compounds 5-aminovalerate and δ-valerolactam are important building blocks that can be used to synthesize bioplastics. The production of 5-aminovalerate and δ-valerolactam in microorganisms provides an ideal source that reduces the cost. To achieve efficient biobased coproduction of 5-aminovalerate and δ-valerolactam in Escherichia coli, a single biotransformation step from L-lysine was constructed. First, an equilibrium mixture was formed by L-lysine α-oxidase RaiP from Scomber japonicus. In addition, by adjusting the pH and H2O2 concentration, the titers of 5-aminovalerate and δ-valerolactam reached 10.24 and 1.82 g/L from 40 g/L L-lysine HCl at pH 5.0 and 10 mM H2O2, respectively. With the optimized pH value, the δ-valerolactam titer was improved to 6.88 g/L at pH 9.0 with a molar yield of 0.35 mol/mol lysine. The ratio of 5AVA and δ-valerolactam was obviously affected by pH value. The ratio of 5AVA and δ-valerolactam could be obtained in the range of 5.63:1–0.58:1 at pH 5.0–9.0 from the equilibrium mixture. As a result, the simultaneous synthesis of 5-aminovalerate and δ-valerolactam from L-lysine in Escherichia coli is highly promising. To our knowledge, this result constitutes the highest δ-valerolactam titer reported by biological methods. In summary, a commercially implied bioprocess developed for the coproduction of 5-aminovalerate and δ-valerolactam using engineered Escherichia coli.

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“…PCH 194 has been shown to produce 11.0 ± 1.0 g L −1 PHB (i.e., 58% of CDW) from 40 g L −1 of glucose. [ 43 ]…”

Section: Microbial Sources Selection and Diversity In Nutritional Requirementsmentioning

confidence: 99%

Process optimization, metabolic engineering interventions and commercialization of microbial polyhydroxyalkanoates production – A state‐of‐the art review

Lhamo

Behera

Mahanty

2021

Biotechnology Journal

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Background Microbial polyhydroxyalkanoates (PHAs) produced using renewable resources could be the best alternative for conventional plastics. Despite their incredible potential, commercial production of PHAs remains very low. Nevertheless, sincere attempts have been made by researchers to improve the yield and economic viability of PHA production by utilizing low‐cost agricultural or industrial wastes. In this context, the use of efficient microbial culture or consortia, adoption of experimental design to trace ideal growth conditions, nutritional requirements, and intervention of metabolic engineering tools have gained significant attention. Purpose and scope This review has been structured to highlight the important microbial sources for PHA production, use of conventional and non‐conventional substrates, product optimization using experimental design, metabolic engineering strategies, and global players in the commercialization of PHA in the past two decades. The challenges about PHA recovery and analysis have also been discussed which possess indirect hurdle while expanding the horizon of PHA‐based bioplastics. Summary Selection of appropriate microorganism and substrate plays a vital role in improving the productivity and characteristics of PHAs. Experimental design‐based bioprocess, use of metabolic engineering tools, and optimal product recovery techniques are invaluable in this dimension. Conclusion Optimization strategies, which are being explored in isolation, need to be logically integrated for the successful commercialization of microbial PHAs.

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Bioprocess for co-production of polyhydroxybutyrate and violacein using Himalayan bacterium Iodobacter sp. PCH194

Cited by 35 publications

References 45 publications

Laser Processing of Polymer Films Fabricated from PHAs Differing in Their Monomer Composition

Laser Processing of Polymer Films Fabricated from PHAs Differing in Their Monomer Composition

Coproduction of 5-Aminovalerate and δ-Valerolactam for the Synthesis of Nylon 5 From L-Lysine in Escherichia coli

Process optimization, metabolic engineering interventions and commercialization of microbial polyhydroxyalkanoates production – A state‐of‐the art review

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