Some plants do not grow due to the high pH levels of ecological concrete pore solutions. In this paper, we design and build an integrated device featuring a combined microbial film and a transverse/U-shaped grouting film. We have applied to the China Intellectual Property Office for an invention patent on this device. The device overcomes the blockage of the grouting port caused by microbial and vertical grouting. The vertical grouting tube leaves holes inside a specimen, reducing the compressive strength, while the integrated device optimizes and decreases variation in the recycling of microbial bacteria. The reduction in the pore alkalinity of porous ecological concrete resulting from the microbial grouting film of this device is larger than that resulting from a microbial sprayed film. The pH values of porous ecological concrete with microbial grouting films and microbial sprayed films are obtained by the pure slurry soaking method and solid–liquid extraction method, respectively. The pH value is lower for the film obtained by the pure slurry soaking method than for that obtained by the solid–liquid extraction method. Conversely, the pH value of porous ecological concrete with a microbial grouting film is reduced to approximately 8 at an age of 56 days. The compressive strengths of the porous ecological concrete specimens with the two films are almost the same. The results of this study provide the necessary theoretical basis for developing alkali reduction technology for porous ecological concrete with environmental and economic benefits.

Background Community-acquired pneumonia (CAP) is a common and serious condition that can be caused by a variety of pathogens. However, much remains unknown about how these pathogens interact with the lower respiratory commensals, and whether any correlation exists between the dysbiosis of the lower respiratory microbiota and disease severity and prognosis.Methods We conducted a retrospective cohort study to investigate the composition and dynamics of sputum microbiota in patients diagnosed with CAP. In total, 917 sputum specimens were collected consecutively from 350 CAP inpatients enrolled in six hospitals following admission. The V3-V4 region of the 16 S rRNA gene was then sequenced.Results The sputum microbiota in 71% of the samples were predominately composed of respiratory commensals. Conversely, 15% of the samples demonstrated dominance by five opportunistic pathogens. Additionally, 5% of the samples exhibited sterility, resembling the composition of negative controls. Compared to non-severe CAP patients, severe cases exhibited a more disrupted sputum microbiota, characterized by the highly dominant presence of potential pathogens, greater deviation from a healthy state, more significant alterations during hospitalization, and sparser bacterial interactions. The sputum microbiota on admission demonstrated a moderate prediction of disease severity (AUC = 0.74). Furthermore, different pathogenic infections were associated with specific microbiota alterations. Acinetobacter and Pseudomonas were more abundant in influenza A infections, with Acinetobacter was also enriched in Klebsiella pneumoniae infections.Conclusion Collectively, our study demonstrated that pneumonia may not consistently correlate with severe dysbiosis of the respiratory microbiota. Instead, the degree of microbiota dysbiosis was correlated with disease severity in CAP patients.

AIMS:The aim was to characterize indigenous micro-organisms in oil reservoirs after polymer flooding (RAPF).METHODS:The microbial communities in the crude oil phase (Oil) and in the filter-graded aqueous phases Aqu0.22 (>0.22 μm) and Aqu0.1 (0.1-0.22 μm) were investigated by 16S rRNA gene high-throughput sequencing.RESULTS:Indigenous micro-organisms related to hydrocarbon degradation prevailed in the three phases of each well. However, obvious differences in bacterial compositions were observed amongst the three phases of the same well and amongst the same phase of different wells. The crude oil and Aqu0.22 shared many dominant bacteria. Aqu0.1 contained a unique bacterial community in each well. Most bacteria in Aqu0.1 were affiliated to culturable genera, suggesting that they may adapt to the oil reservoir environment by reduction of cell size. Contrary to the bacterial genera, archaeal genera were similar in the three phases but varied in relative abundances. The observed microbial differences may be driven by specific environmental factors in each oil well.CONCLUSIONS:The results suggest an application potential of microbial enhanced oil recovery (MEOR) technology in RAPF. The crude oil and Aqu0.1 contain many different functional micro-organisms related to hydrocarbon degradation. Both should not be overlooked when investing and exploring the indigenous micro-organisms for MEOR.SIGNIFICANCE AND IMPACT OF THE STUDY:This work facilitates the understanding of microbial community structures in RAPF and provides information for microbial control in oil fields.

Bioleaching of tannery sludge is an efficient and environmentally friendly way for chromium (Cr) removal, which supports the sustainable development of the leather industry. Acidithiobacillus thiooxidans has been reported effective in Cr bioleaching of tannery sludge. However, little is known about whether the presence of other benefiting species could further improve the Cr leaching efficiency of A. thiooxidans. Here, we studied the enhancing roles of four species namely Acidiphilium cryptum, Sulfobacillus acidophilus, Alicyclobacillus cycloheptanicus, and Rhodotorula mucilaginosa in chromium bioleaching of tannery sludge with A. thiooxidans by batch bioleaching experiments. We found that each of the four species facilitated the quick dominance of A. thiooxidans in the bioleaching process and significantly improved the bioleaching performance including bioleaching rate and efficiency. The bioleaching efficiency of Cr in the tannery sludge could reach 100% on the sixth day by co-inoculating A. thiooxidans and four auxiliary species. The achievements shed a light on the role of the community-level interactions on bioleaching and may also serve as guidance for managing bioleaching consortiums for better outcomes.

Ammonia inhibition easily affects the performance of anaerobic digestion (AD) for municipal sludge and the oxidization of volatile fatty acids (VFAs) is the rate-limiting step of this process. Bioaugmentation is considered to be an effective method to alleviate ammonia inhibition of AD, but most study used the hydrogenotrophic methanogens as the bioaugmentation culture. In this study, bioaugmentation of mesophilic AD (MAD) and thermophilic AD (TAD) under ammonia inhibition with syntrophic acetate and propionate oxidizing consortia was investigated. The results showed that the bioaugmented reactors recovered earlier than control reactors with 20 (MAD) and 8 (TAD) days, respectively. The high-throughput 16S rRNA gene sequencing indicated that the relative abundance of carbohydrates fermenter (Lentimicrobium), syntrophic VFAs-oxidizing bacteria (Rikenellaceae_DMER64, Smithella and Syntrophobacter) and acetoclastic and hydrogenotrophic methanogens (Methanosaeta, Methanolinea and Methanospirillum) increased in MAD after bioaugmentation. However, part of the bioaugmentation culture could not adapt to the high free ammonia (FAN) concentration in MAD and the effect was weakened. In TAD, proteolytic bacteria (Keratinibaculum and Tepidimicrobium), syntrophic VFAs-oxidizing bacteria (Syntrophomonas) and hydrogenotrophic methanogen (Methanosarcina) were strengthened. The effect of bioaugmentation in TAD was durable even at higher organic loading rate (OLR), due to its positive influence on microbial community. These results suggested that the different bioaugmentation mechanism occurred in MAD and TAD, which are derived from the synergetic effects of ammonia tolerance and microbial interactions. Our study revealed the VFAs-oxidizing consortia as bioaugmented culture could be the potential strategy to alleviate the ammonia stress of AD.

The shear strength (vertical pressure 50, 100, 200, and 300 kPa) and soil structure of the remolded loess with different proportions of the microbial cementing solution were measured and observed by the direct shear test and scanning electron microscopy (SEM).The results showed: (1) the increase in the microbial cementation solution led to the transformation of the stress-shear displacement curve from strain hardening to strain softening, with the transition interval of 26%∼34%. (2) With the increase in the microbial cementation solution, the change of cohesion showed a trend of “M,” the inflection point of the microbial cementation solution was 14%, 22%, and 34%, while the internal friction angle showed a law of “W,” where the inflection points of the internal friction angle were about 14%, 30%, 34%, and 38%, respectively. In the range of 18%∼30%, the cohesion and internal friction angle increase with an increase in the microbial cementation solution.(3) The change of cohesion is affected by the microbial mineralization saturation and the joint action of the occurrence state of Ca2+ and HCO3- in the microbial cementation solution. The change of internal friction angle is affected by the soil particle contact, the existing form of calcium carbonate formed by microbial precipitation, pore morphology, yield, and other forces. (4) By means of SEM, the distribution morphology of the soil particles and the contact microscopic images of the loess samples modified by microorganisms with different proportions were further verified to further verify the macroscopic changes of the shear strength of the modified loess samples cemented by microorganisms with different proportions. It provides a theoretical basis for the improvement of loess soil structure characteristics by microorganism calcium carbonate precipitation technology.

Microbial metabolism of crude oil is an important process in both microbial enhanced oil recovery and bioremediation. Recently, diverse microorganisms have been detected and isolated from oil reservoirs. In this work, crude oil- and asphaltene-degrading microcosms were constructed using two different reservoir production water samples, which had distinct bacterial communities. After two three-week enrichments culture, GC-MS and FT-IR analysis showed that crude oil and asphaltene were biodegraded. Microbial communities in microcosms using the same carbon source showed high similarity, which suggested similar processes of microbial succession in both crude oil- and asphaltene-degrading consortia. Parvibaculum, Pseudomonas, Alcanivorax, Devosia, Hydrogenophaga and Dietzia were found in all crude oil degrading microcosms and Parvibaculum, Alcanivorax, Hyphomonas, Flavobacterium and Reyranella were found in all asphaltene degrading microcosms, which might play important roles in crude oil or asphaltene degradation. The results indicated that reservoir production water might serve as a microbial species pool which contained the indigenous core microbiomes for crude oil degradation. This work provided new insights into the understanding of microbial diversity in reservoir production water and the potential role of reservoir production water as a microbial species pool for oil degrading microorganisms.

Taking natural coal as a "seed bank" of bacterial strains able to degrade lignin that is with molecular structure similar to coal components, we isolated 393 and 483 bacterial strains from a meager lean coal sample from Hancheng coalbed and a brown coal sample from Bayannaoer coalbed, respectively, by using different media. Statistical analysis showed that isolates were significantly more site-specific than medium-specific. Of the 876 strains belonging to 27 genera in Actinobacteria, Firmicutes, and Proteobacteria, 612 were positive for lignin degradation function, including 218 strains belonging to 35 species in Hancheng and 394 strains belonging to 19 species in Zhongqi. Among them, the dominant lignin-degrading strains were Thauera (Hancheng), Arthrobacter (Zhongqi) and Rhizobium (both). The genes encoding the laccases- or laccase-like multicopper oxidases, key enzymes in lignin production and degradation, were detected in three genera including Massila for the first time, which was in high expression by real time PCR (qRT-PCR) detection, confirming coal as a good seed bank.

Although various studies have been conducted in screening oil-degrading microorganisms and the macroscale degrading efficiency, critical processes of microorganisms in the microscale porous space are not clear, which are important for microbial enhanced oil recovery (MEOR) and bioremediation of oil contaminated environments. In this work a gas-permeable microchannel filled with crude oil was employed to study the microbial processes in a microscale environment. Cells of a petroleum-degrading Dietzia strain were suspended with two different media and the resulting suspensions were ejected into the microchannel. The degradation processes in the oil–suspension system were then analyzed. The changes in the behavior of the cells and the variation of the oil–suspension interface as well as the evolution of the suspension patterns and structures were observed. ‘Aggregates’, ‘clustered cells’, and ‘oil droplets’ were characteristically formed in comparison with the control experiments. Oil droplets were formed at the oil–suspension interface and dispersed into the suspension, and this process could be drastic that a plume of oil droplets was issuing into the suspension. All the changes could be attributed to the degradation of crude oil by the cells and the production of biosurfactants which could reduce the interface tension and increase the dissolution of the crude oil. The present work is a preliminary step toward a comprehensive understanding of microbial process in microscale porous space.

Four bacterial strains were isolated from a crude oil contaminated saline soil in Shengli Oilfield, China. Strains SL014B-28A2T and SL014B-80A1 were most closely related to Rubrimonas cliftonensis OCh 317T, while strains SL003B-26A1T and SL003B-26A2 were most closely related to but readily different from the species in the Pannonibacter–Labrenzia–Roseibium–Stappia cluster. The major fatty acids were C18:1 ω7c, C16:0, C18:0 and 11-Methyl C18:1 ω7c, and C18:1 ω7c, 11-Methyl C18:1 ω7c and C18:0, respectively, for these two groups of isolates. Q-10 was the predominant ubiquinone. The G + C contents of genomic DNA of the four isolates were 67.9, 69.7, 65.6 and 65.6 mol%. Based on the polyphasic taxonomic characteristics, strains SL014B-28A2T and SL014B-80A1 represented a novel species of the genus Rubrimonas, for which the name Rubrimonas shengliensis sp. nov. is proposed, with strain SL014B-28A2T (=LMG 26072T = CGMCC 1.9170T) as the type strain. Isolates SL003B-26A1T and SL003B-26A2 represented a novel genus and species of the family Rhodobacteraceae, for which the name Polymorphum gilvum gen. nov., sp. nov. is proposed, with strain SL003B-26A1T (=LMG 25793T = CGMCC 1.9160T) as the type strain.

Four bacterial strains, SL014B-41A4(T), SL014B-20A1(T), SL014B-76A1 and SL014B-79A, isolated from a crude oil-contaminated saline soil of Shengli Oilfield, China, were investigated using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain SL014B-41A4(T) belonged to the genus Salinarimonas in the order Rhizobiales, with the highest sequence similarity with Salinarimonas rosea YIM YD3(T) (98.3 %). The DNA-DNA relatedness of strain SL014B-41A4(T) to S. rosea YIM YD3(T) was 27.03 ± 3.0 %. Strain SL014B-41A4(T) was Gram-negative staining, facultatively anaerobic and produced deep red pigment in artificial seawater medium. Cells of strain SL014B-41A4(T) were rod-shaped (0.6-4.0 × 1.25-25 µm), motile with a single polar flagellum and often formed branches. The strain contained Q-10 as the predominant respiratory ubiquinone and C(18 : 1)ω7c (57.5 %), C(16 : 0) (16.4 %) and 10-methyl C(19 : 0) (9.1 %) as the major fatty acids. Strains SL014B-20A1(T), SL014B-76A1 and SL014B-79A were actinobacteria and belonged to the genus Tessaracoccus in the family Propionibacteriaceae of the order Actinomycetales with the highest 16S rRNA gene sequence similarities with Tessaracoccus flavescens SST-39(T) (96.4 %), Tessaracoccus lubricantis KISS-17Se(T) (96.2 %) and Tessaracoccus bendigoensis Ben 106(T) (94.7 %). Strains SL014B-20A1(T), SL014B-76A1 and SL014B-79A were Gram-positive staining, facultatively anaerobic, non-endospore-forming, non-motile, acid-fast and oval to rod-shaped (0.48 × 0.5-1.0 µm). These three novel strains had ll-diaminopimelic acid (DAP) as the diagnostic diamino acid in the cell-wall peptidoglycan, MK-9(H(4)) as the only menaquinone and anteiso-C(15 : 0) (67.11-76.14 %) as the major cellular fatty acid. The G+C contents of the genomic DNA of strain SL014B-41A4(T) and strains SL014B-20A1(T), SL014B-76A1 and SL014B-79A were 67.68 mol% and 65.65-67.17 mol%, respectively. Based on phenotypic and genotypic characteristics, strain SL014B-41A4(T) represents a novel species of the genus Salinarimonas, for which the name Salinarimonas ramus is proposed, with strain SL014B-41A4(T) ( = DSM 22962(T) = CGMCC 1.9161(T)) as the type strain. Strains SL014B-20A1(T), SL014B-76A1 and SL014B-79A represent a novel species of the genus Tessaracoccus, for which the name Tessaracoccus oleiagri is proposed, with strain SL014B-20A1(T) ( = DSM 22955(T) = CGMCC 1.9159(T)) as the type strain.