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In the present study, bacterial-algal coupling system, an integration process of acidogenic fermentation and microalgae cultivation was used for high strength mariculture wastewater (HSMW) treatment, resource recovery and low-cost biomass production. The effect of temperature on Chlorella vulgaris (C. vulgaris) cultivation was investigated with culture medium of acidogenic liquid. The results showed that acidogenic liquid could be used as culture medium for C. vulgaris and higher biomass was obtained compared to control...

In the life cycle of Neopyropia yezoensis, a potential model system for marine macroalgae, both of asexual archeospores and meiosis-related conchospores develop into thalli (gametophyte). To understand this special life phenomenon in macroalgae, we picked out the two kinds of spores (10-30 cells in each sample) and conducted RNA-seq using Smart-seq2. Comparative analysis showed that light capture and carbon fixation associated differentially expressed genes (DEGs) were upregulated in archeospores, thus indicating that archeospores are in a state of rapid vegetative growth...

Mariculture wastewater generated from the mariculture industry has increased public concern due to its impact on the sustainability of aquatic environments and aquaculture practices. Herein, the Bacterial-Algal Coupling System was applied for mariculture wastewater treatment. Microalgae growth in heterotrophy and mixotrophy (2000-8000 lux) were first compared. The best microalgal growth and nutrient removal were obtained at 5000 lux, where biomass productivity of microalgae was 0.465 g L-1 d-1 , and 98...

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BACKGROUND: Diatoms contribute 20% of the global primary production and are adaptable in dynamic environments. Diatoms always bloom earlier in the annual phytoplankton succession instead of dinoflagellates. However, how diatoms acclimate to a dynamic environment, especially under changing light conditions, remains unclear. RESULTS: We compared the growth and photosynthesis under fluctuating light conditions of red tide diatom Skeletonema costatum, red tide dinoflagellate Amphidinium carterae, Prorocentrum donghaiense, Karenia mikimotoi, model diatom Phaeodactylum tricornutum, Thalassiosira pseudonana and model dinoflagellate Dinophycae Symbiodinium...

In this study, Bacterial-Algal Coupling System, a method integrated acidogenic fermentation (AF) and microalgae cultivation, was applied to the mariculture wastewater (MW) treatment. The MW was acidogenic fermented at different initial pH (4.0-10.0), and different dilution rate (5%-20%) of AF effluent was used for Chlorella vulgaris cultivation. The results showed that the maximum biomass production (5.6 g/L) of microalgae was obtained with 10% AF effluent. Ammonium, phosphate and volatile fatty acids could be metabolized by microalgae...

The red macroalga Pyropia yezoensis is an economically important seaweed widely cultured in Asian countries, and is a model organism for molecular biological and commercial research. This species is unique in that it utilizes both phycobilisomes and transmembrane light harvesting proteins as its antenna system. Here, one of the genes of P. yezoensis (PyLHCI) was selected for introduction into its genome to overexpress PyLHCI. However, the co-suppression phenomenon occurred. This is the first documentation of co-suppression in algae, in which it exhibits a different mechanism from that in higher plants...

BACKGROUND: Pyropia yezoensis (Rhodophyta) is widely cultivated in East Asia and plays important economic, ecological and research roles. Although inorganic carbon utilization of P. yezoensis has been investigated from a physiological aspect, the carbon concentration mechanism (CCM) of P. yezoensis remains unclear. To explore the CCM of P. yezoensis, especially during its different life stages, we tracked changes in the transcriptome, photosynthetic efficiency and in key enzyme activities under different inorganic carbon concentrations...

Although biotechnologies for astaxanthin production from Haematococcus pluvialis have been developed for decades and many production facilities have been established throughout the world, the production cost is still high. This paper is to evaluate the current production processes and production facilities, to analyze the R&D strategies for process improvement, and to review the recent research advances shedding light on production cost reduction. With these efforts being made, we intent to conclude that the production cost of astaxanthin from Haematococcus might be substantially reduced to the levels comparable to that of chemical astaxanthin through further R&D and the future research might need to focus on strain selection and improvement, cultivation process optimization, innovation of cultivation methodologies, and revolution of extraction technologies...

With depletion of fossil fuel, microalgae is considered as a promising substitute due to high growth rate, efficient cost and high biofuels content. This study investigated the effect of temperature on mixotrophic cultivation of Chlorella vulgaris. In addition, the combination carbon source of inorganic (HCO3 - or CO3 2- ) and organic (glucose or acetate) for microalgae cultivation was evaluated to obtain the optimum carbon source for mixotrophic cultivation. The results showed that the optimum temperature of microalgae cultivation was at the range of 15-20 °C...

Biological denitrification using mariculture solid wastes (MSW) carbon source is a promising solution for removing nitrate (NO3 - -N) and disposing MSW in marine recirculating aquaculture systems (RAS). To enhance denitrification performance, heating (HT), rhamnolipid (RL), alkali (AL), thermophilic bacteria (TB) pre-treated MSW acidogenic fermentation effluents were prepared as carbon sources. Profiles of soluble organics in four types of fermentation effluents were first evaluated. The highest volatile fatty acids (VFAs) yield (52...

PGRL1-dependent cyclic electron transport (CET) around photosystem I (PSI) plays important roles in response to different stresses, including high light. Although the function of PGRL1 in higher plants and green algae have been thoroughly investigated, little information is available on the molecular mechanism of PGRL1 in diatoms. We created PGRL1 overexpression and knockdown transformants of Phaeodactylum tricornutum, the diatom model species, and investigated the impact on growth and photosynthesis under constant and fluctuating light conditions...

To understand the denitrification efficiency and microbial community shift with increasing salinity in salinity adaptation and shock loading process, nitrate (NO3 - -N), nitrite (NO2 - -N) and chemical oxygen demand (COD) removal efficiencies were monitored feeding acetate and primary sludge fermentation liquid. During adaptation process, salinity had little effect on NO3 - -N removal efficiency (>99.0%) with acetate-fed, while for fermentation liquid-fed, it decreased to around 97% at high salinity (>2...

Heterotrophic denitrification using mariculture solid wastes (MSW) fermentation liquid as carbon source is an economically and environmentally sustainable strategy for NO3 - -N removal in marine recycling aquaculture systems (RAS). The optimization of COD/NO3 - -N ratio (C/N) and hydraulic retention times (HRT) with respect to MSW fermentation liquid driven denitrification for marine RAS wastewater treatment was investigated. The optimum C/N of 8 and HRT of 6 h for heterotrophic denitrification was obtained with NO3 - -N removal efficiency of 97...

Nonphotochemical quenching (NPQ) is an important photoprotective mechanism in plants, which dissipates excess energy and further protects the photosynthetic apparatus under high light stress. NPQ can be dissected into a number of components: qE, qZ and qI. In general, NPQ is catalyzed by two independent mechanisms, with the faster-activated quenching catalyzed by the monomeric light-harvesting complex (LHCII) proteins and the slowly activated quenching catalyzed by LHCII trimers, both processes depending on zeaxanthin but to different extent...

Background: Fucoxanthin (FX), a xanthophyll pigment which occurs in marine brown algae with remarkable biological properties, has been proven to be safe for consumption by animals. Although FX has various pharmacological effects including anti-inflammatory, anti-tumor, anti-obesity, antioxidant, anti-diabetic, anti-malarial, and anti-lipid, in vivo protective effect against sepsis has not been reported. In this study, we aimed at evaluation the efficacy of the FX in a model of sepsis mouse. Methods: FX was successfully isolated from Conticribra weissflogii ND-8 for the first time...

BACKGROUND: Numerous studies have shown that stress induction and genetic engineering can effectively increase lipid accumulation, but lead to a decrease of growth in the majority of microalgae. We previously found that elevated CO2 concentration increased lipid productivity as well as growth in Phaeodactylum tricornutum, along with an enhancement of the oxidative pentose phosphate pathway (OPPP) activity. The purpose of this work directed toward the verification of the critical role of glucose-6-phosphate dehydrogenase (G6PDH), the rate-limiting enzyme in the OPPP, in lipid accumulation in P...

BACKGROUND: Increasing CO2 emissions have resulted in ocean acidification, affecting marine plant photosynthesis and changing the nutrient composition of marine ecosystems. The physiological and biochemical processes of marine phytoplankton in response to ocean acidification have been reported, but have been mainly focused on growth and photosynthetic physiology. To acquire a thorough knowledge of the molecular regulation mechanisms, model species with clear genetic background should be selected for systematic study...

Salt stress is a major abiotic stress factor that can induce many adverse effects on photosynthetic organisms. Plants and algae have developed several mechanisms that help them respond to adverse environments. Non-photochemical quenching (NPQ) is one of these mechanisms. The thalli of algae in the intertidal zone that are attached to rocks can be subject to salt stress for a short period of time due to the rise and fall of the tide. Ulva prolifera causes green tides and can form floating mats when green tides occur and the upper part of the thalli is subjected to high salt stress for a long period of time...

A mutant strain of Pyropia yezoensis, strain E, was isolated from the free living conchocelis of a pure strain (NA) treated with ethyl methane sulfonate. The incremental quantities of young strain E blades were higher than those of NA after 14 d of cultivation, indicating that young blades of mutant strain E released more archeospores. The mean length and weight of large E blades were both over three times greater than those of NA after 4 weeks of cultivation. The photosynthetic parameters (Fv/Fm, Y[I], Y[II], and O2 evolution rate) and pigment contents (including phycoerythrin and phycocyanin) of strain E blades were higher than those of NA (p<0...