The electrochemical ion membrane system (EIMs) enhanced light reactions of photosynthesis with intermittent electrical stimulation.

Despite the widespread application of electrochemical systems in bioproduction, their detailed effects on photosynthetic organisms remain to be explored. In this study, a three-chamber electrochemical ion membrane system (EIMs) was optimized for minimizing carbon resource interference in the cathode chamber, thereby elucidating the role of EIMs in the light reactions of photosynthesis. By applying intermittent electrical stimulation, the photosynthetic activity of microalgae was enhanced, manifesting as the promoted accumulation of intracellular ATP and NADPH, while allowing the collection of hydrogen and oxygen as by-products.

Enhancement of astaxanthin accumulation via energy reassignment by removing the flagella of Haematococcus pluvialis.

Astaxanthin biosynthesis in Haematococcus pluvialis is driven by energy. However, the effect of the flagella-mediated energy-consuming movement process on astaxanthin accumulation has not been well studied. In this study, the profiles of astaxanthin and NADPH contents in combination with the photosynthetic parameters with or without flagella enabled by pH shock were characterized.

Improved production of andrimid in Erwinia persicina BST187 strain by fermentation optimization.

Background: Andrimid is reported to be a novel kind of polyketide-nonribosomal peptide hybrid product (PK-NRPs) that inhibits fatty acid biosynthesis in bacteria. Considering its great potential in biomedicine and biofarming, intensive studies have been conducted to increase the production of andrimid to overcome the excessive costs of chemosynthesis. In screening for species with broad-spectrum antibacterial activity, we detected andrimid in the fermentation products of Erwinia persicina BST187.

Technologies for harvesting the microalgae for industrial applications: Current trends and perspectives.

Microalgae are emerging as a promising source for augmenting the supply of essential products to meet global demands in an environmentally sustainable manner. Despite the potential benefits of microalgae in industry, the high energy consumption for harvesting remains a significant obstacle. This review offers a comprehensive overview of microalgae harvesting technologies and their industrial applications, with particular emphasis on the latest advances in flocculation techniques.

The current situations and limitations of genetic engineering in cyanobacteria: a mini review.

Cyanobacteria are an ancient group of photoautotrophic prokaryotes, and play an essential role in the global carbon cycle. They are also model organisms for studying photosynthesis and circadian regulation, and metabolic engineering and synthetic biology strategies grants light-driven biotechnological applications to cyanobacteria, especially for engineering cyanobacteria cells to achieve an efficient light-driven system for synthesizing any product of interest from renewable feedstocks. However, lower yield limits the potential of industrial application of cyanobacterial synthetic biology, and some key limitations must be overcome to realize the full biotechnological potential of these versatile microorganisms.

Insights into carbon utilization under mixotrophic conditions in Chlamydomonas.

Mixotrophic microalgae cultivation with various carbon resources is considered as a strategy that could increase biomass. However, the mechanism of carbon utilization between inorganic carbon (IC) and organic carbon (OC) remains unknown. In this study, IC and OC consumption, chlorophyll fluorescence parameters, intracellular Nicotinamide adenine dinucleotide phosphate content and transcriptional changes in related genes were characterized.

Using δF as a potential biomarker for risk assessment of environmental pollutants in aquatic ecosystem: A case study of marine cyanobacterium Synechococcus sp. PCC7002.

Increased hazardous substances application causes more environmental pollution and risks for human health. Microalgae are the important biological groups in marine ecosystem, and considered to be sensitive to environmental pollutants. Therefore, toxicity test on marine microalgae could provide the most efficient method for aquatic toxicity assessment, and could also be used as the early warning signals in aquatic ecosystem.

Small peptide glutathione-induced bioflocculation for enhancing the food application potential of Chlorella pyrenoidosa.

Existing flocculants are used to enhance the harvesting efficiency of microalgae; however, harvesting biomass containing residues is unsuitable for food applications. In this study, a small peptide-induced bioflocculation technique was developed for harvesting microalgae, and the biomass was free of impurities. After seven days of cultivation with glutathione, 72 % flocculation efficiency of Chlorella pyrenoidosa was achieved after settling for 1 h.

A Novel Salt-Bridge Electroflocculation Technology for Harvesting Microalgae.

Microalgae biomass, as a promising alternative feedstock, can be refined into biodiesel, pharmaceutical, and food productions. However, the harvesting process for quality biomass still remains a main bottleneck due to its high energy demand. In this study, a novel technique integrating alkali-induced flocculation and electrolysis, named salt-bridge electroflocculation (SBEF) with non-sacrificial carbon electrodes is developed to promote recovery efficiency and cost savings.

Transcriptome analysis of lipid metabolism in response to cerium stress in the oleaginous microalga Nannochloropsis oculata.

Nannochloropsis oculata can accumulate large amounts of lipids under rare earth element (REE) conditions. However, the lipid accumulation mechanism responsible for REE stress has not been elucidated. In this study, the effects of cerium (the most abundant REE) on the growth and lipid accumulation of N.

Transcriptome analysis of Haematococcus pluvialis of multiple defensive systems against nitrogen starvation.

Haematococcus pluvialis could accumulate large amounts of triacylglycerol (TAG) and astaxanthin under various environmental stresses. To gain insights into the multiple defensive systems for carbon metabolism against nitrogen starvation, transcriptome analysis was performed. It was found that the genes related to carbon fixation, glycolysis, fatty acid and carotenoid biosynthesis pathways were up-regulated remarkably.

Enhancement of linoleic acid content stimulates astaxanthin esterification in Coelastrum sp.

Most natural astaxanthin is fatty acid-esterified in microalgae to prevent oxidation. However, the factors influencing astaxanthin esterification (AE) are poorly understood. In this study, obstacles to AE in Coelastrum sp.

A Mathematical Model of Neutral Lipid Content in terms of Initial Nitrogen Concentration and Validation in sp. HA-1 and Application in .

Microalgae are considered to be a potential major biomass feedstock for biofuel due to their high lipid content. However, no correlation equations as a function of initial nitrogen concentration for lipid accumulation have been developed for simplicity to predict lipid production and optimize the lipid production process. In this study, a lipid accumulation model was developed with simple parameters based on the assumption protein synthesis shift to lipid synthesis by a linear function of nitrogen quota.

CAH1 and CAH2 as key enzymes required for high bicarbonate tolerance of a novel microalga Dunaliella salina HTBS.

Outdoor microalgal cultivation with high concentration bicarbonate has been considered as a strategy for reducing contamination and improving carbon supply efficiency. The mechanism responsible for algae's strong tolerance to high bicarbonate however, remains not clear. In this study, we isolated and characterized a strain and revealed its high bicarbonate tolerant mechanism by analyzing carbonic anhydrase (CA).

Hydroxyl radical-aided thermal pretreatment of algal biomass for enhanced biodegradability.

Background: Algal biomass, known as a potential feedstock for biofuel production, has cell wall structures that differ from terrestrial biomass. The existing methods for processing algae are limited to conventional pretreatments for terrestrial biomass.

Results: In this study, we investigated a novel hydroxyl radical-aided approach for pretreating different types of algal biomass.

Ethanol induced astaxanthin accumulation and transcriptional expression of carotenogenic genes in Haematococcus pluvialis.

Haematococcus pluvialis is one of the most promising natural sources of astaxanthin. However, inducing the accumulation process has become one of the primary obstacles in astaxanthin production. In this study, the effect of ethanol on astaxanthin accumulation was investigated.