Nitrate and oxygen significantly changed the abundance rather than structure of sulphate-reducing and sulphur-oxidising bacteria in water retrieved from petroleum reservoirs.

Sulphate-reducing bacteria (SRB) are the main culprits of microbiologically influenced corrosion in water-flooding petroleum reservoirs, but some sulphur-oxidising bacteria (SOB) are stimulated when nitrate and oxygen are injected, which control the growth of SRB. This study aimed to determine the distributions of SRB and SOB communities in injection-production systems and to analyse the responses of these bacteria to different treatments involving nitrate and oxygen. Desulfovibrio, Desulfobacca, Desulfobulbus, Sulfuricurvum and Dechloromonas were commonly detected via 16S rRNA gene sequencing.

A laboratory study of the increasing competitiveness of Karenia mikimotoi under rising CO scenario.

Ocean acidification (OA) driven by elevated carbon dioxide (CO) levels is expected to disturb marine ecological processes, including the formation and control of harmful algal blooms (HABs). In this study, the effects of rising CO on the allelopathic effects of macroalgae Ulva pertusa to a toxic dinoflagellate Karenia mikimotoi were investigated. It was found that high level of CO (1000 ppmv) promoted the competitive growth of K.

Functional characterization of common carp (Cyprinus carpio) AHRs: Subform-specific sensitivity to dioxin and interspecies differences.

Dioxins are widely known to bioaccumulate in the body and produce a wide spectrum of toxic effects on both humans and wildlife. In addition, some novel sorts of compounds that were similar in structure and effect were gradually identified and termed dioxin-like compounds (DLCs). The toxicity of dioxins as well as DLCs is predominantly mediated by the dioxin receptor (aryl hydrocarbon receptor, AHR) in animals, which is usually differentially expressed and functionally distinct (especially the sensitivity to dioxins) among species, possibly resulting in species-specific variations in the toxicity of dioxins.

Sulfur-oxidizing bacteria (SOB) and sulfate-reducing bacteria (SRB) in oil reservoir and biological control of SRB: a review.

Sulfur-oxidizing bacteria (SOB) and sulfate-reducing bacteria (SRB) inhabit oilfield production systems. Sulfur oxidation driven by SOB and dissimilatory sulfate reduction driven by SRB play important roles in sulfur cycle of oil reservoirs. More importantly, hydrogen sulfide produced by SRB is an acidic, flammable, and smelly toxic gas associated with reservoir souring, corrosion of oil-production facilities, and personnel safety.

Regional distribution of the plastic additive tris(butoxyethyl) phosphate in Nanyang Lake estuary, China, and toxic effects on Cyprinus carpio.

There is increasing concern regarding the toxicological effects of plastic additives on humans and aquatic organisms. This study investigated effects of the plastic additive tris(butoxyethyl) phosphate (TBEP) on Cyprinus carpio by measuring concentration distribution of TBEP in the Nanyang Lake estuary, as well as toxic effects of varying doses of TBEP exposure on carp liver. This also included measuring responses of superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and cysteinyl aspartate-specific protease (caspase).

Metabolites and metabolic pathways associated with allelochemical effects of linoleic acid on Karenia mikimotoi.

Linoleic acid (LA) shows great potential in inhibiting the growth of multiple red tide microalgae by disturbing algal physio-biochemical processes. However, our knowledge on the mechanisms of algal mortality at metabolic level remains limited. Herein, the response of K.

Coal-mining subsidence changed distribution of the microbiomes and their functional genes in a farmland.

Land subsidence is a serious geological event, and can trigger severe environmental and ecological issues. In this study, the influences of coal-mining subsidence on distribution of farmland microbiomes and their functional genes were investigated by 16 S ribosomal RNA (rRNA) gene and metagenome sequencing. The results showed the existence of a core microbiome, which determined the community compositions across the subsidence farmland.

Highly efficient and recyclable Z-scheme heterojunction of AgPO/g-CN floating foam for photocatalytic inactivation of harmful algae under visible light.

Harmful algal blooms (HABs) have frequently occurred worldwide, causing marine ecosystems and human health risks. As an advanced and green oxidation technology, photocatalysis has potential to remove red tide algae using solar energy. Herein, in this work, Z-scheme photocatalysts of AgPO/g-CN (APCN) floating foam with different mass ratios were fabricated for the algae inactivation.

Effects comparison between the secondary nanoplastics released from biodegradable and conventional plastics on the transfer of antibiotic resistance genes between bacteria.

Antibiotic resistance genes (ARGs) have caused widespread concern because of their potential harm to environmental safety and human health. As substitutes for conventional plastics, the toxic effects of short-term degradation products of biodegradable plastics (polylactic acid (PLA) and polyhydroxyalkanoates (PHA)) on bacteria and their impact on ARGs transfer were the focus of this study. After 60 days of degradation, more secondary nanoplastics were released from the biodegradable plastics PLA and PHA than that from the conventional plastics polystyrene (PS).

Photocatalytic degradation effect and mechanism of Karenia mikimotoi by non-noble metal modified TiO loading onto copper metal organic framework (SNP-TiO@Cu-MOF) under visible light.

In this study, the SNP-TiO@Cu-MOF composite was prepared successfully by loading non-noble metal modified TiO (SNP-TiO) on the surface of copper metal organic skeleton (Cu-MOF), and compared the inactivation efficiency of different photocatalysts to Karenia mikimotoi (K. mikimotoi) under visible light. The obtained photocatalyst had the characteristic crystal faces of Cu-MOF and SNP- TiO, and contained functional groups such as Cu-O, -COOH, N-O, P-O, etc.

Acidification of seawater attenuates the allelopathic effects of Ulva pertusa on Karenia mikimotoi.

Acidification of seawater resulting from absorption of excessive carbon dioxide from the atmosphere is posing a serious threat to marine ecosystem. In this study, we hypothesized that acidified seawater attenuates allelopathic effects of macroalgae on red tide algae because the increase of dissolved carbon dioxide benefits algal growth, and investigated the allelopathic effects of Ulva pertusa on Karenia mikimotoi in response to seawater acidification by determining cell density, photosynthetic pigment content, chlorophyll fluorescence parameters, and chloroplast structure of K. mikimotoi under U.

Toxic effect of triphenyl phosphate (TPHP) on Cyprinus carpio and the intestinal microbial community response.

Triphenyl phosphate (TPHP) is a kind of organophosphorus flame retardants, and its use is increasing annually. However, the toxic effect associated with exposure to it has not been adequately investigated. Therefore, in this study, we determined the toxic dose of TPHP in the economic fish species, Cyprinus carpio.

The inactivation effects and mechanisms of Karenia mikimotoi by non-metallic elements modified TiO (SNP-TiO) under visible light.

As an advanced oxidation technology, photocatalytic treatment of red tide algae pollution was potential of great research prospects. However, the most commonly used photocatalyst TiO can only use ultraviolet light with short wavelength because of its wide band gap. In this study, the non-metallic elements S, N and P were added into the TiO (SNP-TiO) lattice by hydrothermal synthesis, and the inactivation effects and mechanisms of Karenia mikimotoi were studied under visible light.

Biochemical and Physiological Responses of Harmful to Algicidal Bacterium O-4.

Harmful algal blooms caused by frequently occur worldwide and severely threaten the marine environment. In this study, the biochemical and physiological responses of to the algicidal bacterium O-4 were investigated, and the effects on the levels of reactive oxygen species (ROS), malondialdehyde content, multiple antioxidant systems and metabolites, photosynthetic pigments, and photosynthetic index were examined. The cell-free supernatant in strain O-4 significantly inhibited cell growth.

Bacterial and Archaeal Community Distribution in Oilfield Water Re-injection Facilities and the Influences from Microorganisms in Injected Water.

Water flooding is widely employed for oil production worldwide. However, there has never been a systematic investigation of the microbial communities occurring in oilfield water re-injection facilities. Here, we investigated the distribution of bacterial and archaeal communities in water re-injection facilities of an oilfield, and illustrated the combined influences of environmental variation and the microorganisms in injected water on the microbial communities.

Disentangling the distinct mechanisms shaping the subsurface oil reservoir bacterial and archaeal communities across northern China.

Microbes in surface ecosystem exhibit strong biogeographic patterns, and are less apparent after human management. However, in contrast with the considerable knowledge on the surface ecosystem, the microbial biogeographic patterns in deep subsurface ecosystem under artificial disturbance is poorly understood. Here, we explored the spatial scale-dependence patterns of bacterial and archaeal communities in oil reservoirs under different artificial flooding duration and environmental conditions across northern China.

Algicidal activity of a novel indigenous bacterial strain of Paracoccus homiensis against the harmful algal bloom species, Karenia mikimotoi.

Harmful algal blooms have deleterious effects on aquatic ecosystems and human health. The application of algicidal bacteria is a promising and environmentally friendly method of preventing and eradicating harmful algal blooms. In this study, a screen for algicidal agents against harmful algal blooms was used to identify an algicidal bacterial strain (strain O-4) isolated from a Karenia mikimotoi culture.

Biomarker responses and histological damage in the gill, liver, and gonad of Cyprinus carpio with benzo(a)pyrene exposure.

The risk of polycyclic aromatic hydrocarbon exposure in aquatic organisms is a global concern. In this study, we investigated the toxic effects of different doses of benzo(a)pyrene (BaP) on Cyprinus carpio in microcosms from the following aspects: superoxide dismutase (SOD) and peroxidase (POD) activity, malondialdehyde (MDA) content in the gill, liver, and gonad; glutathione s-transferase (GST), aromatic hydroxylase (AHH), and 7-ethoxyresorufin-O-deethylase (EROD) activity in the liver; and altered tissue and cellular structures of the gill, liver,and gonad. SOD and POD activity in the gill, liver, and gonad increased in low-dose BaP groups and significantly decreased with an increase in BaP.

Occurrence of antibiotic resistance genes in an oilfield's water re-injection systems.

The recent widespread increase in antibiotic resistance has become a real threat to both human and environmental ecosystem health. In oil reservoirs, an extreme environment potentially influenced by human activity such as water flooding, the distribution and abundance of antibiotic resistance genes (ARGs) remains poorly understood. Herein, we investigated the distribution of ARGs at different positions in a water-flooding oilfield in China, and found that ARGs were observed in all parts of the investigated system.

Feasible Green Strategy for the Quantitative Bioaccumulation of Heavy Metals by Lemna minor: Application of the Self-Thinning Law.

This study involved the development of mathematical linear regression models to describe the relationships between mean plant biomass (M) and population density (D), M and frond diameter (L), frond numbers (N) and L of Lemna minor under different initial population densities (3200, 4450, and 6400 plants/m), respectively, from the perspective of the self-thinning law. Our results revealed that the value of the allometric exponents for M and D were - 3/2. Further, the concentrations of Zn, Pb, Cu, Fe, and Ni accumulated in L.

Low-Abundance Inhabiting a Water-Flooding Oil Reservoir and the Application Potential for Oil Recovery.

With the development of molecular ecology, increasing low-abundance microbial populations were detected in oil reservoirs. However, our knowledge about the oil recovery potential of these populations is lacking. In this study, the oil recovery potential of low-abundance that accounts for less than 0.

Composition of Bacterial and Archaeal Communities in an Alkali-Surfactant-Polyacrylamide-Flooded Oil Reservoir and the Responses of Microcosms to Nutrients.

The microbial communities in alkali-surfactant-polyacrylamide-flooded (ASP-flooded) oil reservoirs have rarely been investigated compared to those in water-flooded oil reservoirs. Here, the bacterial and archaeal communities in an ASP-flooded reservoir and the adjacent water-flooded block, and responses of the microbial communities in microcosms to nutrients were investigated by 16S rRNA gene sequencing and cultivation. Compared with the water-flooded block, both the bacterial and archaeal communities inhabiting the ASP-flooded block had lower Sobs indices (91:232 and 34:55, respectively), lower Shannon indices (1.

Effects of okadaic acid and hematein on human lung adenocarcinoma A549 cells and responses of mitochondria and endoplasmic reticulum apoptosis pathways.

Background: Okadaic acid (OA) and hematein are both able to inhibit the proliferation of human lung adenocarcinoma A549 cells. However, it is largely unknown about their combined effects on proliferation and apoptosis of A549 cells.

Methods: The combined effects of the two drugs on proliferation of A549 cells and the responses of mitochondria and endoplasmic reticulum (ER) apoptosis pathways were investigated.

Optimizing Culture Conditions by Statistical Approach to Enhance Production of Pectinase from sp. Y1.

It was found that sp. Y1 could secrete alkaline pectinase with suitable enzyme system for powerful and fast degumming of ramie fiber. In this study, the medium components and fermentation conditions were optimized by some statistical methods including mixture design, fractional factorial design, central composite design and response surface methodology, and single factor method for enhancing the alkaline pectinase production.