The marine environment is a highly diverse reservoir of microalgae, many of which remain poorly characterized. Diatoms are widely recognized as promising sources of high-value bioactive compounds, including fucoxanthin. A marine diatom strain was isolated from the coast of Sfax, Tunisia. The isolated strain was identified both morphologically and genetically as Halamphora sp. closely related to Halamphora calidilacuna (98.92
This review covers biochemistry, thermochemical, and hybrid conversion processes for plastic waste valorization. The available literature lists these technologies individually. There is no comparative framework for intentional mixing across technology families. This review fills this gap by comparing four aspects: polymer applicability, product yield, energy requirements, and net carbon recovery. There are three main Principles. Mild biological pretreatment with subsequent thermochemical upgrading in hybrid systems enables recovery of monomers at lower energy input as compared to solely thermochemical processes. Enzymatic depolymerization of PET and relevant polyesters is technically possible, though scale-up remains challenging. Polyolefins remain resistant to enzymatic attack, and the hybrid thermochemical-biological pathways are the only feasible way forward. Specific knowledge gaps continue to remain. The available biocatalysts are still inefficient on polyolefins. There are no standardized protocols for the integration of hybrids. Industrial-scale life cycle and techno-economic data are still lacking. By measuring comparative strengths and barriers, this review provides a decision-making framework for polymer-specific, scalable recycling approaches.
Pectinase is a group of enzymes, classified as protopectinases, esterases, and depolymerases, commonly known to break down the complex plant polysaccharide pectin by the hydrolysis of α-(1–4) glycosidic bonds. These catalysis produces products like oligogalacturonates, monomeric galacturonic acid, and methanol. Pectinase has extensive applications in a number of industries like food and beverages, paper and pulp, wastewater treatment, feed, bioethanol production, oil extraction, textiles, leather sectors, etc. About 25
D-xylose is an important pentose platform sugar for producing xylitol, furfural, xylonic acid, succinic acid, and other value-added chemicals. However, conventional D-xylose production mainly relies on xylan-rich lignocellulosic hydrolysates, which require harsh pretreatment and energy-intensive purification, limiting process controllability and sustainability. Here, a D-glucose-based modular biocatalytic platform was developed for de novo D-xylose production in Escherichia coli BL21 (DE3). The pathway was divided into an upstream precursor-supply module, comprising glk, zwf, pgl, and gnd to strengthen oxidative pentose phosphate pathway flux, and a downstream D-xylose-forming module, comprising rpe, araL, and xylA to channel D-xylulose−5-phosphate toward free D-xylose. Screening of the key dephosphorylation step identified the cascade reaction containing Bacillus atrophaeus AraL as the most effective system, which yielded 1.38 g/L D-xylose. N-terminal truncation generated the AraL36 variant, which further increased D-xylose production to 1.95 g/L. Subsequent host rewiring by deleting pgi and xylB redirected D-glucose-derived carbon toward pentose-phosphate precursors and reduced D-xylulose re-phosphorylation, improving D-xylose production to 2.16 g/L. In an optimized crude-enzyme biocatalytic system, 100 mM D-glucose was converted into 66.41 mM D-xylose within 20 h, corresponding to 9.97 g/L D-xylose and 66.41
Residual veterinary antibiotics represent a major class of organic pollutants that threaten ecological environments and human health. Cytochrome P450 enzymes (CYP450s), a large superfamily of heme-containing monooxygenases, exhibit broad substrate tolerance and have attracted substantial interest for pollutant biotransformation. Previous reviews have covered the structural biology and xenobiotic metabolism of CYP450s. Yet few studies have combined CYP450-related findings for antibiotic pollutants and investigated bottlenecks limiting CYP450-driven remediation of antibiotic contamination. This review presents the structural features, classification, and electron-transfer chains of CYP450s from different origins, along with their catalytic cycles for pollutant transformation. Experimental evidence is compiled from purified-enzyme-assays, genetic-validation, inhibitor-based tests, and whole-cell studies to distinguish direct CYP450-catalyzed biotransformation from downstream microbial degradation, detoxification, and mineralization. Practical barriers are further discussed, including low substrate coupling efficiency, poor environmental stability, cofactor dependence, and metabolite ecotoxicity. Optimizing strategies including rational protein design, fusion-protein construction, enzyme immobilization, and catalytic microenvironment tuning are evaluated. These strategies also point out critical gaps between laboratory findings and field implementation. Unresolved challenges, biosafety risks, scale-up constraints, and future research priorities are summarized. This review provides practical references for developing CYP450-based biotechnologies to remediate antibiotic contamination.
