Evaluation of a novel anti-biofouling microorganism (Bacillus sp. T5) for control of membrane biofouling and its effect on bacterial community structure in membrane bioreactors

Abstract This study aimed to address the gap in understanding how the microbial community present within quorum quenching-membrane bioreactor (QQ-MBRs) changes during the operations by investigating the behavior of two different types of QQ bacteria, Bacillus sp. T5 and Delftia sp. T6. The anti-biofouling effects of T5 and T6 in the QQ-MBR were 85% and 76%, respectively. According to the Illumina HiSeq results, when the QQ-MBR was operated with Gram-positive bacteria, T5, in the mixed liquor a reduction was observed in Gram-positive bacteria and Gram-negative bacteria population increased. In contrast, when the QQ-MBR was operated with Gram-negative bacteria, T6, Gram-negative bacteria population reduced and an increase in Gram-positive bacteria observed. As such, the outputs of the Illumina analysis revealed that use of Gram-negative QQ bacteria in the reactor induced a Gram-positive microbial community and vice versa. This indicates that a close interaction occurs between indigenous Gram-negative and positive bacterial phyla, and Bacillus sp. T5/Delftia sp. T6 is fundamental to the performance of MBRs. This is the first study demonstrating such a relationship and assistance selecting QQ bacteria/strategy in an effective way.

Download Full-text

Influence of Aged Biochar Modified by Cd2+ on Soil Properties and Microbial Community

Sustainability ◽

10.3390/su12124868 ◽

2020 ◽

Vol 12 (12) ◽

pp. 4868

Author(s):

Kun Li ◽

Guangcai Yin ◽

Qiuyuan Xu ◽

Junhua Yan ◽

Zeng-Yei Hseu ◽

...

Keyword(s):

Microbial Community ◽

Soil Properties ◽

Microbial Communities ◽

Physicochemical Characteristics ◽

Sorption Process ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Cadmium Adsorption

Biochar is a promising addition for cadmium-contaminated soil in-situ remediation, but its surface properties change after aging, cadmium adsorption is not well-documented, and subsequent environmental effects are still unknown. In this study, wood-derived (Eucalyptus saligna Sm.) biochar was pre-treated to simulate aging and the cadmium sorption process. We then analyzed the resulting physicochemical characteristics. We conducted comparative incubation studies on three age stages of biochar under cadmium adsorption or no cadmium adsorption and then measured soil properties and microbial communities after incubation. Biochar addition raised soil organic carbon (SOC), and aging significantly increased C/N ratios. Aged biochar promoted higher microbial abundance. Aged biochar treatments possessed different microflora with more gram-positive bacteria, significantly altering gram-positive/gram-negative bacteria ratios. Aging significantly increased the oxygen-containing functional groups (OCFGs) and surface area (SA) of biochar. Thus, aged biochar adsorbed more cadmium. Cadmium-binding biochar increased the proportion of gram-negative bacteria and decreased the proportions of gram-positive bacteria and fungi. Similar patterns in phospholipid fatty acids (PLFAs) across adsorption treatments indicated that changes in microbial communities due to the effects of cadmium were confined. The results reveal that biochar aging altered microbial community structure and function more than cadmium binding.

Download Full-text

Bacterial community assemblages in classroom floor dust of 50 public schools in a large city: characterization using 16s rRNA sequences and associations with environmental factors

10.21203/rs.3.rs-64047/v3 ◽

2020 ◽

Author(s):

Ju-Hyeong Park ◽

Angela R. Lemons ◽

Jerry Roseman ◽

Brett J. Green ◽

Jean M. Cox-Ganser

Keyword(s):

Bacterial Community ◽

Dna Sequences ◽

Epidemiologic Study ◽

Large City ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Floor Dust ◽

Bacterial Assemblages

Abstract Characterizing indoor microbial communities using molecular methods provides insight into bacterial assemblages present in environments that can influence occupants’ health. We conducted an environmental assessment as part of an epidemiologic study of 50 elementary schools in a large city in the northeastern United States. We vacuumed dust from the edges of the floor in 500 classrooms accounting for 499 processed dust aliquots for 16S Illumina MiSeq sequencing to characterize bacterial assemblages. DNA sequences were organized into operational taxonomic units (OTUs) and identified using a database derived from the National Center for Biotechnology Information. Bacterial diversity and ecological analyses were performed at the genus level. We identified 29 phyla, 57 classes, 148 orders, 320 families, 1,193 genera, and 2,045 species in 3,073 OTUs. The number of genera per school ranged from 470 to 705. The phylum Proteobacteria was richest, followed by Firmicutes, Actinobacteria, Bacteroidetes, and Cyanobacteria while Firmicutes was most abundant. The most abundant order included Lactobacillales, Spirulinales, Clostridiales, Bacteroidales, Pseudomonadales, and Micrococcales. Halospirulina was the most abundant genus (the only genus within the order Spirulinales), followed by Lactobacillus, Streptococcus, Sphingomonas, Clostridium, and Pseudomonas. Gram-negative bacteria were more abundant and richer (relative abundance=0.53;1,632 OTUs) than gram-positive bacteria (0.47; 1,441). The Bray-Curtis dissimilarity index ranged from 0.22 to 0.63, with a median of 0.40. Effects of school location, degree of water damage, building condition, number of students, air temperature and humidity, floor material, and classroom’s floor level on the bacterial richness or community composition were statistically significant but subtle. Our study indicates that classroom floor dust had a characteristic bacterial community represented by more gram-negative bacteria, in comparison to typical house dust that is represented by more gram-positive bacteria. Health implications of exposure to the microbiomes in classroom floor dust may be different from those in homes for school staff and students.

Download Full-text

Bacterial Community Assemblages in Classroom Floor Dust of 50 Public Schools in a Large City: Characterization Using 16s rRNA Sequences and Associations with Environmental Factors

10.21203/rs.3.rs-64047/v1 ◽

2020 ◽

Author(s):

Ju-Hyeong Park ◽

Angela R. Lemons ◽

Jerry Roseman ◽

Brett J. Green ◽

Jean M. Cox-Ganser

Keyword(s):

Bacterial Community ◽

Dna Sequences ◽

Epidemiologic Study ◽

Large City ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Floor Dust ◽

Bacterial Assemblages

Abstract Characterizing indoor microbial communities using molecular methods provides insight into bacterial assemblages present in environments that can influence occupants’ health. We conducted an environmental assessment as part of an epidemiologic study of 50 elementary schools in a large city in the northeastern United States. We vacuumed dust from the edges of the floor in 500 classrooms accounting for 499 processed dust aliquots for 16S Illumina MiSeq sequencing to characterize bacterial assemblages. DNA sequences were organized into operational taxonomic units (OTUs) and identified using a database derived from the National Center for Biotechnology Information. Bacterial diversity and ecological analyses were performed at the genus level. We identified 29 phyla, 57 classes, 148 orders, 320 families, 1,193 genera, and 2,045 species in 3,073 OTUs. The number of genera per school ranged from 470 to 705. The phylum Proteobacteria was richest, followed by Firmicutes, Actinobacteria, Bacteroidetes, and Cyanobacteria while Firmicutes was most abundant. The most abundant order included Lactobacillales, Spirulinales, Clostridiales, Bacteroidales, Pseudomonadales, and Micrococcales. Halospirulina was the most abundant genus (the only genus within the order Spirulinales), followed by Lactobacillus, Streptococcus, Sphingomonas, Clostridium, and Pseudomonas. Gram-negative bacteria were more abundant and richer (relative abundance=0.53;1,632 OTUs) than gram-positive bacteria (0.47; 1,441). The Bray-Curtis dissimilarity index ranged from 0.22 to 0.63, with a median of 0.40. Effects of school location, degree of water damage, building condition, number of students, air temperature and humidity, floor material, and classroom’s floor level on the bacterial richness or community composition were statistically significant but subtle. Our study indicates that classroom floor dust had a characteristic bacterial community represented by more gram-negative bacteria, in comparison to typical house dust that is represented by more gram-positive bacteria. Health implications of exposure to the microbiomes in classroom floor dust may be different from those in homes for school staff and students.

Download Full-text

Stable Vesicle Production from Bacterial Total Lipid Extracts

Abasyn Journal Life Sciences ◽

10.34091/ajls.4.1.1 ◽

2021 ◽

pp. 1-10

Author(s):

Sana Fatima ◽

Naila Malkani ◽

Muhammad Muzammal ◽

Asghar Ali Khan ◽

Muhammad Usama

Keyword(s):

Total Lipid ◽

Cell Structure ◽

Lipid Extraction ◽

Structural Basis ◽

Bacillus Sp ◽

Environmental Condition ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Gram Positive Bacteria

The current study aims to produce stable liposomes from total lipid extracts from bacteria. Liposomes are the small vesicles that are made up of lipids. On their structural basis, they can be considered as simplified cell structure of cell membrane. Structure of liposomes depends on the pH of preparation buffer, method of preparation and the environmental condition in which they are prepared. Liposomes have importance in the field of medicines for diagnostic and therapeutic purposes. They mainly work as a vehicle for drug delivery. The objective of the current study was to make stable liposomes from two types of bacterial samples i.e., a Gram-positive and a Gram-negative strain. E. coli and Bacillus sp. were selected as representative of Gram-negative and Gram-positive bacteria, respectively. Lipid extraction was performed by various methods, out of which the modified Bligh and Dyer method gave most effective results. Liposomes were prepared by extrusion and their stability and efficiency was tested by fluorescence spectrophotometer using OxanolVI. Our results showed that liposomes formed by lipids extracted from E. coli were more stable than the liposomes formed by lipids extracted from Bacillus sp. Keywords: liposomes, Lipids, diagnostic, therapeutic, purposes, fluorescence, Bacillus sp.

Download Full-text

Bacterial community assemblages in classroom floor dust of 50 public schools in a large city: characterization using 16s rRNA sequences and associations with environmental factors

10.21203/rs.3.rs-64047/v2 ◽

2020 ◽

Author(s):

Ju-Hyeong Park ◽

Angela R. Lemons ◽

Jerry Roseman ◽

Brett J. Green ◽

Jean M. Cox-Ganser

Keyword(s):

Bacterial Community ◽

Dna Sequences ◽

Epidemiologic Study ◽

Large City ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Floor Dust ◽

Bacterial Assemblages

Abstract Characterizing indoor microbial communities using molecular methods provides insight into bacterial assemblages present in environments that can influence occupants’ health. We conducted an environmental assessment as part of an epidemiologic study of 50 elementary schools in a large city in the northeastern United States. We vacuumed dust from the edges of the floor in 500 classrooms accounting for 499 processed dust aliquots for 16S Illumina MiSeq sequencing to characterize bacterial assemblages. DNA sequences were organized into operational taxonomic units (OTUs) and identified using a database derived from the National Center for Biotechnology Information. Bacterial diversity and ecological analyses were performed at the genus level. We identified 29 phyla, 57 classes, 148 orders, 320 families, 1,193 genera, and 2,045 species in 3,073 OTUs. The number of genera per school ranged from 470 to 705. The phylum Proteobacteria was richest, followed by Firmicutes, Actinobacteria, Bacteroidetes, and Cyanobacteria while Firmicutes was most abundant. The most abundant order included Lactobacillales, Spirulinales, Clostridiales, Bacteroidales, Pseudomonadales, and Micrococcales. Halospirulina was the most abundant genus (the only genus within the order Spirulinales), followed by Lactobacillus, Streptococcus, Sphingomonas, Clostridium, and Pseudomonas. Gram-negative bacteria were more abundant and richer (relative abundance=0.53;1,632 OTUs) than gram-positive bacteria (0.47; 1,441). The Bray-Curtis dissimilarity index ranged from 0.22 to 0.63, with a median of 0.40. Effects of school location, degree of water damage, building condition, number of students, air temperature and humidity, floor material, and classroom’s floor level on the bacterial richness or community composition were statistically significant but subtle. Our study indicates that classroom floor dust had a characteristic bacterial community represented by more gram-negative bacteria, in comparison to typical house dust that is represented by more gram-positive bacteria. Health implications of exposure to the microbiomes in classroom floor dust may be different from those in homes for school staff and students.

Download Full-text

Structure of a Microbial Community in Soil after Prolonged Addition of Low Levels of Simulated Acid Rain

Applied and Environmental Microbiology ◽

10.1128/aem.64.6.2173-2180.1998 ◽

1998 ◽

Vol 64 (6) ◽

pp. 2173-2180 ◽

Cited By ~ 137

Author(s):

Taina Pennanen ◽

Hannu Fritze ◽

Pekka Vanhala ◽

Oili Kiikkilä ◽

Seppo Neuvonen ◽

...

Keyword(s):

Fatty Acids ◽

Microbial Community ◽

Bacterial Community ◽

Acid Rain ◽

Carbon Sources ◽

Simulated Acid Rain ◽

Leucine Incorporation ◽

Acetate Incorporation ◽

Gram Positive ◽

Gram Positive Bacteria

ABSTRACT Humus samples were collected 12 growing seasons after the start of a simulated acid rain experiment situated in the subarctic environment. The acid rain was simulated with H2SO4, a combination of H2SO4 and HNO3, and HNO3 at two levels of moderate acidic loads close to the natural anthropogenic pollution levels of southern Scandinavia. The higher levels of acid applications resulted in acidification, as defined by humus chemistry. The concentrations of base cations decreased, while the concentrations of exchangeable H+, Al, and Fe increased. Humus pH decreased from 3.83 to 3.65. Basal respiration decreased with decreasing humus pH, and total microbial biomass, measured by substrate-induced respiration and total amount of phospholipid fatty acids (PLFA), decreased slightly. An altered PLFA pattern indicated a change in the microbial community structure at the higher levels of acid applications. In general, branched fatty acids, typical of gram-positive bacteria, increased in the acid plots. PLFA analysis performed on the bacterial community growing on agar plates also showed that the relative amount of PLFA specific for gram-positive bacteria increased due to the acidification. The changed bacterial community was adapted to the more acidic environment in the acid-treated plots, even though bacterial growth rates, estimated by thymidine and leucine incorporation, decreased with pH. Fungal activity (measured as acetate incorporation into ergosterol) was not affected. This result indicates that bacteria were more affected than fungi by the acidification. The capacity of the bacterial community to utilize 95 different carbon sources was variable and only showed weak correlations to pH. Differences in the toxicities of H2SO4 and HNO3 for the microbial community were not found.

Download Full-text

Microbiology of a Nitrite-Oxidizing Bioreactor

Applied and Environmental Microbiology ◽

10.1128/aem.64.5.1878-1883.1998 ◽

1998 ◽

Vol 64 (5) ◽

pp. 1878-1883 ◽

Cited By ~ 118

Author(s):

Paul C. Burrell ◽

JÃ¯Â¿Â½rg Keller ◽

Linda L. Blackall

Keyword(s):

Microbial Community ◽

Batch Reactor ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Complex Microbial Community ◽

Seed Sludge ◽

Biological Methods ◽

Sample Dilution ◽

Culture Dependent

ABSTRACT The microbiology of the biomass from a nitrite-oxidizing sequencing batch reactor (NOSBR) fed with an inorganic salts solution and nitrite as the sole energy source that had been operating for 6 months was investigated by microscopy, by culture-dependent methods, and by molecular biological methods, and the seed sludge that was used to inoculate the NOSBR was investigated by molecular biological methods. The NOSBR sludge comprised a complex and diverse microbial community containing gram-negative and gram-positive rods, cocci, and filaments. By culture-dependent methods (i.e., micromanipulation and sample dilution and spread plate inoculation), 16 heterotrophs (6 gram positive and 10 gram negative) were identified in the NOSBR sludge (RC), but no autotrophs were isolated. 16S ribosomal DNA clone libraries of the two microbial communities revealed that the seed sludge (GC) comprised a complex microbial community dominated byProteobacteria (29% beta subclass; 18% gamma subclass) and high G+C gram-positive bacteria (10%). Three clones (4%) were closely related to the autotrophic nitrite-oxidizer Nitrospira moscoviensis. The NOSBR sludge was overwhelmingly dominated by bacteria closely related to N. moscoviensis (89%). Two clone sequences were similar to those of the genusNitrobacter. Near-complete insert sequences of eight RC and one GC N. moscoviensis clone were determined and phylogenetically analyzed. This is the first report of the presence of bacteria from the Nitrospira phylum in wastewater treatment systems, and it is hypothesized that these bacteria are the unknown nitrite oxidizers in these processes.

Download Full-text

Microanatomy of the Periplasm of Bacillus Licheniformis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065365 ◽

1971 ◽

Vol 29 ◽

pp. 262-263

Author(s):

B.K. Ghosh

Keyword(s):

Cell Wall ◽

Plasma Membrane ◽

Bacillus Licheniformis ◽

External Environment ◽

Permeability Barrier ◽

Periplasmic Space ◽

Modified Technique ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria

Periplasm of bacteria is the space outside the permeability barrier of plasma membrane but enclosed by the cell wall. The contents of this special milieu exterior could be regulated by the plasma membrane from the internal, and by the cell wall from the external environment of the cell. Unlike the gram-negative organism, the presence of this space in gram-positive bacteria is still controversial because it cannot be clearly demonstrated. We have shown the importance of some periplasmic bodies in the secretion of penicillinase from Bacillus licheniformis.In negatively stained specimens prepared by a modified technique (Figs. 1 and 2), periplasmic space (PS) contained two kinds of structures: (i) fibrils (F, 100 Å) running perpendicular to the cell wall from the protoplast and (ii) an array of vesicles of various sizes (V), which seem to have evaginated from the protoplast.

Download Full-text

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100123830 ◽

1992 ◽

Vol 50 (1) ◽

pp. 686-687

Author(s):

Jacob S. Hanker ◽

Paul R. Gross ◽

Beverly L. Giammara

Keyword(s):

Chronic Arthritis ◽

Blood Cultures ◽

Gram Negative Bacteria ◽

Infectious Arthritis ◽

Bacterial Arthritis ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

Download Full-text