PhaC Synthases and PHA Depolymerases: The Enzymes that Produce and Degrade Plastic

Abstract

PHAs are a group of intracellular biodegradable polymer produced by (most) bacteria under unbalanced growth conditions. A series of enzymes are involved in different PHAs synthesis, however PhaC synthases are responsible for the polymerization step. PHAs are accumulated in bacterial cells from soluble to insoluble form as storage materials inside the inclusion bodies during unbalanced nutrition or to save organisms from reduces equivalents. PHAs are converted again to soluble components by another pathways and enzymes for the degradation process. PHAs depolymerases are the responsible enzymes. This review is designed to give the non-specialists a condense background about PHAs especially for researcher and students in medicinal and pharmaceutical filled. ABSTRAK: PHAs (polyhydroxyalkanoate) merupakan sekumpulan polimer terbiodegradasikan intrasel yang dihasilkan oleh (kebanyakan) bakteria di bawah keadaan tumbesaran tak seimbang. Satu rangkaian enzim terlibat dalam sistesis PHAs yang berbeza, namun sintesis PhaC bertanggungjawab dalam peringkat pempolimeran. PHAs dikumpulkan dalam sel bakteria dari bentuk larut dan tak larut sebagai bahan simpan di dalam jasad terangkum semasa nutrisi tak seimbang atau untuk menyelamatkan organisma daripada pengurangan tak keseimbangan. PHAs ditukarkan sekali lagi kepada komponen larut dengan cara lain dan enzim lain untuk proses degradasi. PHAs depoly-merases (enzim yang memangkin penguraian makro molekul kepada molekul yang lebih mudah) merupakan enzim yang bertanggunjawab. Kajian semula ini direka untuk memberi mereka yang bukan pakar, satu ringkasan tentang PHAs terutamanya penyelidik dan penuntut dalam bidang peubatan dan farmaseutikal.

Polyhydroxyalkanoate (PHA) Biopolymer Synthesis by Marine Bacteria of the Malaysian Coral Triangle Region and Mining for PHA Synthase Genes

“…SnapGene software (Version 4.3.7) was used to design the primers ( Table 1 ). According to conserved regions, PhaC enzymes are categorised into several classes [ 24 ]. Using NCBI protein and BLAST tools, the Sphingobacterium mizutaii genome sequence was aligned against the amino acid sequences of all four synthase classes (Class I, II, III, and VI).…”

Using inorganic acids to stop purple phototrophic bacteria metabolism improves PHA recovery at a large scale

“…The PHA production costs until 2018 were 3.1€ kg −1 , significantly higher than the production of fossil-based plastics, which costs 1.05-1.15 € kg −1 [2]. In industrial or large-scale PHA production, the major cost required is for microbial PHA polymer extraction from inside the cell [11]. The extraction process is a major cost factor besides feedstock cost for PHA production.…”

“…However, high production costs are still significant, so commercialization is still not widespread [9,10]. Major expenses in the production of PHA are determined by the fermentation substrate's cost and the polymer's extraction from inside the cell [11]. In the situation when PPB experience a shortage of substrates, they consume PHAs as a source of redox power, energy, and carbon.…”

Molecular Characterization of a Poly-β-Hydroxybutyrate-Producing Microbacterium Isolate

“…Early PHB degrading bacteria were isolated by selection for microorganisms able to utilize PHB as the sole source of carbon and energy. PHAs degrading bacteria differ from each other depending on the type of PHAs they degrade, however some bacteria revealed a rather broad polyester specificity and are able to utilize a wide range of PHAs (Amara and Moawad, 2011).…”