Pyrene Biodegradation by Bacillus spp. Isolated from Coal Tar–Contaminated Soil

Aerobic, mesophilic bacteria from coal tar–contaminated soil were analyzed for pyrene utilization capacity and identified by 16S ribosomal DNA sequencing as members of three genera: Bacillus spp., Pseudomonas sp., and Rhodococcus sp. The soil contained nine different hazardous polyaromatic hydrocarbons (PAHs): benzo[g, h, i]perylene, dibenzo[a, h]anthracene, indeno[1,2,3-c,d]pyrene, pyrene, acenaphthylene, fluorene, phenanthrene, benzo[k]fluoranthene, and benzo[b]fluoranthene. Bacillus spp. (PK-6) MTCC 1005 showed 56.4% utilization of pyrene (C₁₆H₁₀) (50 μg ml^?1) in 4 days, with growth associated biosurfactant activity and resulted in the formation of five new intermediates: phenanthrene (C₁₄H₁₀), 9,10-diphenylphenanthrene (C₂₆H₁₈), 9-methoxyphenanthrene (C₁₅H₁₂O), 5,6,7,8-tetrahydro-1-naphthoic acid (C₁₁H₁₂O₂), and 1,6,7-trimethylnaphthalene (C₁₃H₁₄). The results suggested that Bacillus spp. could be found suitable for practical field application for effective in situ PAH bioremediation.     

Bioaccumulation of Heavy Metals by Endemic Viola Species from the Soil in the Vicinity of the As-Sb-Tl Mine “Allchar”, Republic of Macedonia

Allchar mine is an abandoned arsenic-antimony-thallium deposit located on the north-western part of Ko?uf Mt., Republic of Macedonia. Allchar is a unique deposit within the world, due to the variety of its mineral composition especially and in the high content of thallium. The aim of this work was to assess the level of contamination at this post-mining area as well as to determine the intensity of accumulation of various elements (Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Sb, Sr, Tl, V, and Zn) with focus on As, Sb and Tl, in two endemic Viola species from this locality (Viola allcharensis G. Beck, Viola arsenica G. Beck) and one Balkan endemic species (Viola macedonica Boiss. &; Heldr.). Samples of different plant parts and soil were digested and then analysed by ICP-AES. It was found that the accumulation of As, Sb, and Tl in these endemic species is significantly high. In this study a systematic investigation of the As-Sb-Tl contamination of soils and their bioavailability was carried out using the extraction procedure in order to explore the mobility and potential bioavailability of the As, Sb, and Tl.     

Biologic Control Ability of Plant Growth–Promoting Paenibacillus lentimorbus NRRL B-30488 Isolated from Milk

A plant growth–promoting Paenibacillus lentimorbus NRRL B-30488 (B-30488) was isolated from cows’ milk. Bacterial colonization and growth responses of different plant species after inoculation with B-30488 were evaluated in a controlled environment and in microplot assays. Survival and colonization of B-30488 in the phytosphere of plants and soil was monitored using a chromosomally located rifampicin-marked mutant B-30488 (B-30488R). The strain showed variable ability to invade plants. The interaction between B-30488R and Fusarium oxysporum f. sp. ciceri was studied by scanning electron microscopy. Chitinase and β-1,3-glucanase enzymes were produced when B-30488R was grown in the presence of colloidal chitin as sole carbon source. Deliberate dilution of B-30488R with field soil offers a reliable process for decreasing the cost of bacterial inoculants in developing countries. Seed treatment of chickpea demonstrated significantly (P = 0.05) greater seedling mortality in nonbacterized compared with bacterized seedlings. Bacterization significantly (P = 0.05) improved seed germination, plant height, number of pods/plant^–1, and seed dry weight.     

Non-Sterilized Fermentative Production of Polymer-Grade L-Lactic Acid by a Newly Isolated Thermophilic Strain Bacillus sp. 2–6

Background

The demand for lactic acid has been increasing considerably because of its use as a monomer for the synthesis of polylactic acid (PLA), which is a promising and environment-friendly alternative to plastics derived from petrochemicals. Optically pure l-lactic acid is essential for polymerization of PLA. The high fermentation cost of l-lactic acid is another limitation for PLA polymers to compete with conventional plastics.

Methodology/Principal Findings

A Bacillus sp. strain 2–6 for production of l-lactic acid was isolated at 55°C from soil samples. Its thermophilic characteristic made it a good lactic acid producer because optically pure l-lactic acid could be produced by this strain under open condition without sterilization. In 5-liter batch fermentation of Bacillus sp. 2–6, 118.0 g/liter of l-lactic acid with an optical purity of 99.4% was obtained from 121.3 g/liter of glucose. The yield was 97.3% and the average productivity was 4.37 g/liter/h. The maximum l-lactic acid concentration of 182.0 g/liter was obtained from 30-liter fed-batch fermentation with an average productivity of 3.03 g/liter/h and product optical purity of 99.4%.

Conclusions/Significance

With the newly isolated Bacillus sp. strain 2–6, high concentration of optically pure l-lactic acid could be produced efficiently in open fermentation without sterilization, which would lead to a new cost-effective method for polymer-grade l-lactic acid production from renewable resources.     

The Galactose-Binding Lectin Isolated from Vatairea macrocarpa Seeds Enhances the Effect of Antibiotics Against Staphylococcus aureus–Resistant Strain

Probiotics and Antimicrobial Proteins - The use of natural products together with standard antimicrobial drugs has recently received more attention as a strategy to combat infectious diseases...     

Utilization of Alcohols by Rhodopseudomonas sp. No. 7 Isolated from n-Propanol–Enrichment Cultures

A purple non-sulfur bacterium, Rhodopseudomonas sp. No. 7, was isolated from n-propanol–enrichment cultures under anaerobic-light conditions. Strain No. 7 can produce hydrogen from alcohols. The rate of hydrogen production from n-propanol was 34 μl/hr/mg dry cells. Strain No. 7 showed multiplication by budding and the best growth on n-propanol among other organic compounds tested. But its growth on n-propanol was poor under aerobic-dark conditions. NAD-linked alcohol dehydrogenase, NAD-linked aldehyde dehydrogenase, acyl-CoA synthetase and malate synthetase were found in strain No. 7. These enzymes were constitutive. On the other hand, isocitrate lyase was induced in cells grown on ethanol but not on n-propanol. No activity of phenazine methosulfate-linked alcohol dehydrogenase was detected in strain No. 7.     

Sequence Analysis of Leuconostoc mesenteroides Bacteriophage Φ1-A4 Isolated from an Industrial Vegetable Fermentation

Vegetable fermentations rely on the proper succession of a variety of lactic acid bacteria (LAB). Leuconostoc mesenteroides initiates fermentation. As fermentation proceeds, L. mesenteroides dies off and other LAB complete the fermentation. Phages infecting L. mesenteroides may significantly influence the die-off of L. mesenteroides. However, no L. mesenteroides phages have been previously genetically characterized. Knowledge of more phage genome sequences may provide new insights into phage genomics, phage evolution, and phage-host interactions. We have determined the complete genome sequence of L. mesenteroides phage Φ1-A4, isolated from an industrial sauerkraut fermentation. The phage possesses a linear, double-stranded DNA genome consisting of 29,508 bp with a G+C content of 36%. Fifty open reading frames (ORFs) were predicted. Putative functions were assigned to 26 ORFs (52%), including 5 ORFs of structural proteins. The phage genome was modularly organized, containing DNA replication, DNA-packaging, head and tail morphogenesis, cell lysis, and DNA regulation/modification modules. In silico analyses showed that Φ1-A4 is a unique lytic phage with a large-scale genome inversion (∼30% of the genome). The genome inversion encompassed the lysis module, part of the structural protein module, and a cos site. The endolysin gene was flanked by two holin genes. The tail morphogenesis module was interspersed with cell lysis genes and other genes with unknown functions. The predicted amino acid sequences of the phage proteins showed little similarity to other phages, but functional analyses showed that Φ1-A4 clusters with several Lactococcus phages. To our knowledge, Φ1-A4 is the first genetically characterized L. mesenteroides phage.Bacteriophages are the most abundant biological entities (estimated to be on the order of ≥10³¹) on the planet (9, 18). Phages are ubiquitous in nature and can influence the microbial ecology and genetics of bacteria. Because of their small (usually <60 kb) genomes, phages can provide an excellent model system for studying many biological processes, including DNA replication and genetic evolution. Despite this, many phages remain uncharacterized. Very little is known about phage diversity and phage-host interactions owing to the small number of sequenced phages. Furthermore, the existing phage sequence database is highly biased toward a limited spectrum of phage hosts, namely, Enterobacteriaceae, Bacillus, Staphylococcus, Pseudomonas, Vibrio cholerae, Lactococcus, Streptococcus thermophilus, and S. pyogenes. The majority of host species for sequenced phages are either pathogenic or dairy-related bacteria. Most of the newly sequenced phage genes have no assigned functions or matches in the GenBank database (7).Vegetable fermentations rely on a variety of lactic acid bacteria (LAB). The proper succession of LAB directly determines the quality and safety of the final fermentation products. Leuconostoc mesenteroides initiates most vegetable fermentations. It converts the sugars in vegetables (primarily glucose and fructose) to lactic acid, acetic acid, ethanol, CO₂, and other flavor compounds (22, 58, 59, 60, 61). Acid production lowers the pH of fermenting vegetables and inhibits the growth of many microorganisms, including pathogens. CO₂ production promotes the establishment of an anaerobic environment which favors the growth of other LAB. The metabolites produced by L. mesenteroides largely determine the flavor characteristics of the final products. As fermentation proceeds, L. mesenteroides rapidly dies off. Other LAB, including Lactobacillus plantarum, take over and complete the fermentation.It has been a widely held view that the disappearance of L. mesenteroides and the subsequent bacterial succession in sauerkraut fermentations are due to the inhibitory effect of acids that accumulate during fermentation (54, 61). Little is known about other factors that may play a role in bacterial succession. Recent studies have shown that phages are present in the vegetable fermentations (4, 47, 48, 74, 75). Because of the rapid lytic cycle of these phages, they may significantly impact starter cultures and bacterial succession in vegetable fermentations (56). Phages active against L. mesenteroides have been isolated and characterized (48); however, genome sequences have not been reported.L. mesenteroides phage 1-A4 (designated Φ1-A4) is of particular interest. Φ1-A4 is a lytic phage that was repeatedly isolated during the initial stages of a commercial sauerkraut fermentation. As a result, Φ1-A4 may significantly influence the survival of L. mesenteroides and flavor development during sauerkraut fermentation. It was found that Φ1-A4 infects at least three different strains of L. mesenteroides (48), and therefore it may also promote genetic exchange and genetic diversity in microbial communities (34).The objectives of this study were to determine and analyze the complete genome sequence of Φ1-A4, to experimentally identify the structural protein genes, and to compare the genome organization with that of related phages. To our knowledge, this study represents the first complete genomic and molecular characterization of Leuconostoc phage. The results from this study may provide new insights into our understanding of phage genetics. This study may aid the development of phage control technologies in vegetable and other fermentations that are susceptible to phage attack.     

Morphological Variability and Biochemical Parameters of Leaves in Cenopopulations of Aegopodium podagraria L. (Apiаceae,Apiales) under Various Levels of Soil Contamination by Heavy Metals

Biology Bulletin - Abstract—The morphological variability, lipid peroxidation (LPO) rate, and photosynthetic pigment content in leaves of Aegopodium podagraria L. were studied in four...     

Site-directed Mutagenesis of Chitinase from Alteromonas sp. Strain O–7

Chitinase (Chi85) from Alteromonas sp. strain 0–7 contains the two conserved regions common to microbial and plant chitinases. We did site-directed mutagenesis of Chi85 to investigate the effects of the conserved amino acid residues on chitinase activity. We suggest that Asp-290 and Glu-292 of Chi85 may be the essential amino acid residues for the cleavage of β-glycosidic linkage of chitin.     

Evaluation of Iodide and Iodate for Adsorption–Desorption Characteristics and Bioavailability in Three Types of Soil

Adsorption–desorption of iodine in two forms, viz., iodide (I⁻) and iodate (IO₃⁻), in three types of soil were investigated. The soils were: red soil developed on Quaternary red earths (REQ)— clayey, kaolintic thermic plinthite Aquult, Inceptisol soil (IS) and alluvial soil (AS)—Fluvio-marine yellow loamy soil. The isothermal curves of iodine adsorption on soils were described by Langmuir and Freundlich equation, and the maximum adsorption values (y _m) were obtained from the simple Langmuir model. As compared with the iodide, the iodate was adsorbed in higher amounts by the soils tested. Among three soils, the REQ soil adsorbed more iodine (I⁻ and IO₃⁻) than the IS and AS. The distribution coefficient (K _d) of iodine in the soils decreased exponentially with increasing iodine loading concentration. Desorption of iodine in soil was increased correspondingly with increasing adsorption values. The REQ soil had a greater affinity for iodine than the IS and AS at the same iodine loadings. In the pot experiment cultivated with pakchoi (Brassica chinensis L.) and added with two exogenous iodine sources, the iodide form was quickly taken up by pakchoi and caused more toxicity to the vegetable. The rate of iodine loss from soil was higher for iodide form as compared with the iodate. The iodine bioavailability was the highest but the persistence was the weakest in AS among the three soils tested, and the REQ soil showed just the opposite trend to that of the AS soil. This study is of theoretical importance to understand the relationship between iodine adsorption–desorption characteristics and their bioavailability in different soils and it also has practical implications for seeking effective alternatives of iodine biofortification to prevent iodine deficiency disorders.     

Selected Heavy Metals Analysis of Persian Sturgeon’s (Acipenser persicus) Caviar from Southern Caspian Sea

The present research reports the heavy metal (Fe, Cr, Pb, As, and Co) contamination in caviar of Persian sturgeon (Acipenser persicus) caught from Southern Caspian Sea sampling site using ICP-OES. Heavy metal concentrations (microgram per gram, wet weight; means?±?S.D.) in caviar samples were: Fe, 71.33?±?0. 37; Cr, 0.27?±?0.019; Pb, <0.01?±?0.002; As, <0.01?±?0.002; and Co, <0.01?±?0.001, respectively. Comparative evaluation of these metals in different samples showed that except Fe, the average concentrations of Cr, Pb, As, and Co are significantly lower than adverse level for the species themselves and for human consumption when compared with FAO/WHO permissible limits. Therefore, their contribution to adverse health effects on human body can be considered as negligibly small.     

Genomic Analysis of a Mycobacterium Bovis Bacillus Calmette-Guérin Strain Isolated from an Adult Patient with Pulmonary Tuberculosis

For years, bacillus Calmette-Guérin (BCG) has served as the unique vaccine against tuberculosis and has generally been regarded as safe. However, a clinical strain labeled 3281 that was isolated from a TB patient was identified to be BCG. Via the combination of next-generation sequencing (NGS) and comparative genomic analysis, unique 3281 genetic characteristics were revealed. A region containing the dnaA and dnaN genes that is closely related to the initial chromosome replication was found to repeat three times on the BCG Pasteur-specific tandem duplication region DU1. Due to the minimum number of epitopes in BCG strains, 3281 was inferred to have a high possibility for immune evasion. Additionally, variations in the virulence genes and predictions for potential virulence factors were analyzed. Overall, we report a pathogen that has never previously been thought to be pathogenic and initial insights that are focused on the genetic characteristics of virulent BCG.     

Bacteriocins Produced by LAB Isolated from Cheeses within the Period 2009–2021: a Review

A survey is presented concerning original research articles published in well-reputed scientific journals on the isolation of lactic acid bacteria (LAB) from cheeses worldwide, where researchers evaluated the bacteriocin production by such isolates in searching for novel functional peptides that can exhibit potential for biotechnological applications. Seventy-one articles were published in the period of study, with contributions being American (45%), Asiatic (28%), and European (21%), being Brazil-USA-Mexico, Turkey-China, and France-Italy the countries that contributed the most for each said continent, respectively. Most of the isolated LAB belong to the genera Enterococcus (35%), Lactobacillus (30%), Lactococcus (14%), and Pediococcus (10%), coming from soft (64%), hard (27%), and semi-hard (9%) cheeses, predominantly. Also, scholars focused mainly on the food biopreservation (81%) and pharmaceutical field (18%) potential applications.

     

Biological Role of Lectins from the Nitrogen-Fixing <Emphasis Type="Italic">Paenibacillus polymyxa</Emphasis> Strain 1460 During Bacterial–Plant-Root Interactions

Enzyme-lectins LI and LII from Paenibacillus polymyxa 1460, when incubated with the carbohydrate moiety of the wheat-root exocomponent fraction, showed an increase in their proteolytic activity. This increase may be associated with the presence of lectin-specific carbohydrates in the root fraction. The lectins of the nitrogen-fixing paenibacilli enhance cellulose degradation in the plant cell, thus increasing the activity of -glucosidase in the wheat-root cell wall.     

Levels of Heavy Metals and Essential Minerals in Hair Samples of Children with Autism in Oman: a Case–Control Study

Toxic levels of heavy metals and low levels of essential minerals have been suggested to play a critical role in the pathogenesis of autism spectrum disorders (ASD). This study documents the levels of heavy metals and essential minerals in hair samples of children with ASD in Muscat, the urbanized capital of Oman, Muscat. The study included 27 children with ASD and 27 matched non-ASD controls. Parental interviews were held and dietary intake questionnaires completed in conjunction with the collection of hair samples. Analysis of heavy metals and essential minerals was carried out by inductively coupled plasma mass spectrometry. Chi-square analysis and non-parametric Fisher’s exact tests were used to assess statistical significance. Children with ASD had significantly higher levels of all 11 analyzed heavy metals in their hair samples (P?<?0.05), ranging from 150 to 365 % of control levels. ASD children also had significantly higher levels of essential minerals sulfur, sodium, magnesium, potassium, zinc, and iron, but lower levels of calcium and copper in their hair samples. This study corroborates data from previous studies in different parts of the world indicating the presence of elevated levels of heavy metals and selective depletion of essential minerals in the hair of children with ASD.     

Dielectric Properties Based Detection of Heavy Metal Contaminated Soil in the Frequency Range from 10 MHz to 1 GHz

Physical parameters based electromagnetic methods are promising technologies to detect contaminated sites. In these methods, the dielectric property is a key parameter. In this paper, we studied the dielectric characteristics of heavy metal contaminated soil. The chromium contaminated soil was made into samples, and the open-ended coaxial line was adopted as the measurement method. Experiments were conducted in the frequency band between 10 MHz and 1 GHz. The results showed that the complex permittivity, including the real part and the imaginary part, changes as the ionic content changes. Especially, at low frequencies (<50 MHz), the complex permittivity increases significantly with the increase of ionic content. In addition, it also could be seen that the water content of the soil also affects the complex permittivity. We proposed to adopt the drying method or the Time Domain Reflection method to determine the water content. The dielectric parameters are most affected by the ionic content after knowing the water content. Therefore, it is feasible to detect heavy metal contaminated sites based on dielectric properties.     

Degradation of polypropylene–poly-L-lactide blend by bacteria isolated from compost

Abstract

Polypropylene (PP) degrading bacteria (P1 to P16) were isolated from compost using enrichment technique. Five isolates (P3, P6, P8, P10, and P13) were selected based on their degradation abilities. These isolates were identified as Bacillus spp. through biochemical characteristics and 16S rDNA sequence analysis. The isolates were tested for their ability to degrade blends of PP and poly-L-lactide (PLLA) (PP80 and PP80C6) in minimal media as well as in soil. In minimal media, the growth of bacteria increased with time, showing utilization of blend as carbon source. The protein content was estimated at the end of 15?days and maximum amount was secreted by isolate P8 indicating maximum potential to degrade polymers compared to other isolates. Scanning electron microscopy (SEM) results revealed the formation of biofilm on the polymer surface. Fourier-transform infrared spectroscopy (FTIR) analysis showed the formation of new bond at 2123?cm^?1 and breakage of old C=O ester bond at 1757?cm^?1 in case of polymer PP80C6. Thermogravimetric analysis (TGA) showed decrease in thermal stability of polymers after degradation. The carbon dioxide evolved from sample was measured and biodegradation degree was also calculated. The degree of biodegradation shown by the isolate P8 was 12% and the P6 was 10%. The results demonstrated that Bacillus species isolated from composted samples in this study provided promising evidence for the biodegradation of polypropylene and poly-L-lactide (PP-PLLA) blends in the environment.     

The Effect of γ-Radiation and Desiccation on the Viability of the Soil Bacteria Isolated from the Alienated Zone around the Chernobyl Nuclear Power Plant

Methylobacterium extorquens, M. mesophilicum, and Bacillus subtilis strains were found to be resistant to -radiation, irrespective of whether they were isolated from the alienated zone around the Chernobyl Nuclear Power Plant or outside this zone. The LD₉₀ of Methylobacterium and B. subtilis strains with respect to -radiation was 2.0–3.4 and 3.7–4.4 kGy, respectively, whereas their LD_99.99 values were 4.5–6.9 and more than 10 kGy, respectively. The high threshold levels of -radiation for Methylobacterium and B. subtilis imply the efficient functioning of DNA repair systems in these bacteria. Unlike Bacillus polymyxa cells, the cells of M. extorquens, M. mesophilicum, and B. subtilis were also resistant to desiccation. Pseudomonas sp., Nocardiasp., and nocardioform actinomycetes were sensitive to both -radiation and desiccation. Similar results were obtained when the bacteria studied were exposed to hydrogen peroxide and ultraviolet radiation. The results obtained indicate that the bacteria that are resistant to -radiation are also resistant to desiccation, UV radiation, and hydrogen peroxide. The possibility of using common laboratory tests (such as the determination of bacterial resistance to UV light and desiccation) for the evaluation of bacterial resistance to -radiation is discussed.