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Exopolysaccharide Production from Marine Bacteria and Its Applications
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Prashakha J. Shukla, Shivang B. Vhora, Ankita G. Murnal, Unnati B. Yagnik, Maheshwari Patadiya
EPSs are the major fraction of the dissolved organic matter reservoir in the ocean. EPS-producing bacteria have been isolated from different zones of the marine environment, such as the sediment, the deep sea, hydrothermal vents, surface water and mangroves. Some marine bacteria belonging to genera Bacillus, Rhodococcus, Halomonas, Alcanivorax, Pseudomonas, Marinobacter, Pseudoalteromonas and Alteromonas have been isolated for EPS production (Chakraborty et al., 2016). EPSs are high-molecular-weight (HMW) carbohydrate polymers having heteropolymeric composition. EPSs represent an easily available reduced-carbon reservoir for marine organisms in the ocean and help the microbial communities survive under extreme conditions such as high or low temperature, salinity, nutrient availability, pH, pressure and presence of CO2 or O2 (Poli et al., 2010).
Cytochrome P450 Enzymes for the Synthesis of Novel and Known Drugs and Drug Metabolites
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Sanjana Haque, Yuqing Gong, Sunitha Kodidela, Mohammad A. Rahman, Sabina Ranjit, Santosh Kumar
CYP153A has been identified as a fatty acid ω-hydroxylase with a broad substrate range (Honda Malca et al., 2012). CYP153As can be obtained from variety of bacteria including Marinobacter aquaeolei, Alcanivorax borkumensis, and Gordonia alkanivorans (Jung et al., 2016). Recently, the CYP153A enzyme from M. aquaeolei was engineered to a double mutant G307A/S233G based on semi-rational protein design to improve the activity of terminal hydroxylation of medium- and long-chain fatty acids. The most active mutant showed a 3.7-fold improvement over the wild-type activity. Additionally, the heme domain of CYP153A mutant was constructed with the reductase domain of CYPBM3 to improve the catalytic activity for its future industrial applications (Notonier et al., 2016b). Moreover, a crystal structure of CYP153A from M. aquaeolei revealed a crucial target for engineering CYP153A. CYP153A residues at the extended F-helix and Ω-loop were targeted using site-directed mutagenesis. Importantly, mutant P135A showed an enhanced activity on hydroxylation of hexadecanoic acid with 20% more conversion than the wild-type enzyme (Hoffmann et al., 2016).
Biofilms of Halobacterium salinarum as a tool for phenanthrene bioremediation
Published in Biofouling, 2020
Leonardo Gabriel Di Meglio, Juan Pablo Busalmen, César Nicolas Pegoraro, Débora Nercessian
As it can be seen in the phase-contrast micrographs of Figure 5, in the presence of phenanthrene, cells occasionally formed isolated pillars that protruded well over the basal layer of the biofilm. Notably, upon progressive removal of the phenanthrene crystals, some of these pillars were detached from the biofilm (Figure 5, middle-lower panel), as previously observed in biofilms of Mycobacterium sp. LB501T growing on anthracene crystals (Wick et al. 2001). This behavior could also be related to that observed in the hydrocarbonoclastic bacterium Marinobacter hydrocarbonoclasticus SP17, which emigrates from biofilms to colonize free oil-water interfaces while growing on hexadecane droplets (Vaysse et al. 2011). It is worth mentioning that the anchoring sites of pillars were randomly distributed on crystals as well as on the glass surface (Figure 5, middle-lower panel), suggesting that pillar formation does not depend on the hydrophobicity of the substratum. Finally, after complete removal of phenanthrene, the overall structure of the biofilm was similar to that of the controls, although cell density in the upper layers was considerably lower (Figure 3, right upper panels).
Anti-biofilm effect of a butenolide/polymer coating and metatranscriptomic analyses
Published in Biofouling, 2018
Wei Ding, Chunfeng Ma, Weipeng Zhang, Hoyin Chiang, Chunkit Tam, Ying Xu, Guangzhao Zhang, Pei-Yuan Qian
Marine natural products provide a promising reservoir of useful compounds with many marine chemical molecules being reported as potential anti-biofilm agents (reviewed in Clare 1996; Fusetani 2004, 2011; Qian et al. 2009, 2015). For example, Salta et al. (2013) identified toluene from Chondrus crispus, which prevents biofilm formation by the species Cobetia marina and Marinobacter hydrocarbonoclasticus. However, due to technical challenges, such as in situ control of the release rate of these compounds, few compounds have been developed into anti-biofilm agents in marine coatings. One promising solution to the release problem is to utilize polymers with a degradable backbone, which can generate a self-renewing surface in the marine environment and serve as the carrier of anti-biofilm compounds (Ma et al. 2013; Sisson et al. 2013; Babu et al. 2016).
Xenobiotic C-sulfonate derivatives; metabolites or metabonates?
Published in Xenobiotica, 2018
Aromatic C-sulfonate compounds are rare in nature but a few have been reported as bacterial metabolites. Several siderophores (iron chelating proteins) containing a C-sulfonate moiety have been isolated including, 5,6-dihydropyoverdin-7-sulfonate from microbes of the Pseudomonas genus (Budzikiewicz et al., 1998; Marek-Kozaczuk & Skorupska, 1997; Shröder et al., 1995), pseudoalterobactin A and B from marine bacteria of the Pseudoalteromonas genus (Kanoh et al., 2003), and petrobactin sulfonate from oil-degrading microbes (Marinobacter spp.) (Hickford et al., 2004; Homann et al., 2009). Aeruginosin B, a red pigment obtained from Pseudomonas aeruginosa, also contains a sulfonic acid group attached to a carbon atom within the phenazine nucleus (Bentley & Holliman, 1970; Herbert & Holliman, 1964,1969). Although the intricate synthesis routes of some of these compounds have been elucidated, very little is known about the C-sulfonation stage (Welker & von Döhren, 2006). Clear evidence of bacterial enzymes that may catalyze these C-sulfonation reactions has not been forthcoming (Homann et al., 2009). It has been remarked, however, that the majority these sulfonation events occur on benzene rings (usually oxygenated), and as such reflect the first step in the Bucherer-Lepetit reaction (v.i.) (Budzikiewicz, 2006). Interestingly, and also reflecting non-biological routes, the initial reaction in the formation of coenzyme M (2-mercaptoethanesulfonic acid), an essential component required for methyl transfer reactions in methanogenic archaea, is the addition of bisulfite across the carbon-carbon double bond of phosphoenolpyruvate to form sulfolactic acid, which is then further metabolized (White, 1985,1986).