An Acrylamide-degrading Bacterial Consortium Isolated from Volcanic Soi

In soil, polyacrylamide is a key source of acrylamide because it slowly decomposes into acrylamide. There has been a modest but steady rise in worldwide interest in microbe-mediated acrylamide decomposition as a bioremediation method. A bacterial consortium isolated from the volcanic soil of Mount Marapi, West Sumatra, Indonesia, was able to thrive on acrylamide in this study. Acrylamide-degrading bacteria grew best in the presence of 1 %(w/v) glucose with acrylamide as the sole nitrogen source. Optimum growth occurs in between 300 and 500 mg/L of acrylamide, pH between 6.5 and 8.0, and temperatures between 30 and 35 °C. The consortium can also grow on acetamide as the sole nitrogen source. Toxic heavy metals, such as mercury, silver and copper slowed down the growth of this consortium on acrylamide. This is the first report of an acrylamide-degrading consortium isolated from volcanic soils.

Microbial studies of biosurfactant producing bacteria from crude oil contaminated soil

Soils contaminated with crude oil collected from three sites in Delta State were analyzed using serial dilution and pour plate methods. The physicochemical characteristics of the soil were determined using standard methods. The mean heterotrophic bacteria count and the mean hydrocarbon utilizing bacteria count were also determined. Blood haemolysis, foaming activity, oil spreading techniques and emulsification assay was used to screen the microorganisms for biosurfactant production. The biosurfactant producing bacteria were selected and their effect on metal removal and growth kinetics was also determined. The pH of the contaminated soil samples ranged 4.82 to 5.62. The mineral elements such as potassium (k+) and sodium (Na+) ranged from 0.20 to 0.80 Meq/100g and 0.07 to 0.81 Meq/100g respectively. The heavy metal content such as zinc (Zn2+) and lead (Pb2+) ranged from 10.13 to 19.24 mg/kg and 19.24 to 49.63 mg/kg respectively. Organic carbon and THC ranged from 5.44 to 6.87 % and 2720.00 to 3110.00 mg/kg respectively. The mean heterotrophic bacteria and hydrocarbon utilizing bacteria ranges from 1.4 ± 0.4 x 106 to 1.6 ± 0.7 x 106 and 1.0 ± 0.2 x 106 to 1.2 ± 0.4 × 106 respectively in the soil samples. Bacteria isolated and identified from the three sites include Corynebacterium spp., Bacillus subtilis., Pseudomonas aeruginosa, Micrococcus varians, Streptococcus spp., Klebsiella spp. and Enterobacter spp. with Bacillus subtilis and Pseudomonas aeruginosa having the highest prevalence and among these isolates only Corynebacterium spp., Bacillus subtilis., Pseudomonas aeruginosa and Micrococcus varians showed positive result for the production of biosurfactant. Bacillus subtilis had the highest metal removal capacity of 29.44% of 100 ppm of lead. Corynebacterium spp. and Bacillus subtilis had an optimum growth at pH 8 and 7 respectively while Pseudomonas aeruginosa and Micrococcus varians has an optimum growth at pH.

Mariniplasma anaerobium gen. nov., sp. nov., a novel anaerobic marine mollicute, and proposal of three novel genera to reclassify members of Acholeplasma clusters II–IV

A novel strictly anaerobic chemoorganotrophic bacterium, designated Mahy22T, was isolated from sulfidic bottom water of a shallow brackish meromictic lake in Japan. Cells of the strain were Gram-stain-negative, non-motile and coccoid in shape with diameters of about 600–800 nm. The temperature range for growth was 15–37 °C, with optimum growth at 30–32 °C. The pH range for growth was pH 6.2–8.9, with optimum growth at pH 7.2–7.4. The strain grew with NaCl concentrations of 5% or below (optimum, 2–3%). Growth of the strain was enhanced by the addition of thiosulfate. The major cellular fatty acids were C16:0 and anteiso-C15:0. Respiratory quinones were not detected. The complete genome sequence of strain Mahy22T possessed a 1 885 846 bp circular chromosome and a 12 782 bp circular genetic element. The G+C content of the genome sequence was 30.1 mol%. Phylogenetic analysis based on the 16S rRNA gene revealed that the novel strain belonged to the family Acholeplasmataceae , class Mollicutes . The closest relative of strain Mahy22T with a validly published name was Acholeplasma palmae J233T with a 16S rRNA gene sequence similarity of 90.5%. Based on the results of polyphasic analysis, the name Mariniplasma anaerobium gen. nov., sp. nov. is proposed to accommodate strain Mahy22T, along with reclassification of some Acholeplasma species into Alteracholeplasma gen. nov., Haploplasma gen. nov. and Paracholeplasma gen. nov.

Impacts of weaning age on dietary needs of whey permeate for pigs at 7 to 11 kg body weight

Background Whey permeate is an effective lactose source for nursery pigs and the most benefits are obtained when pigs are at 7 to 11 kg BW. Altering weaning ages could cause different length of early-weaner phases until 7 kg BW and thus it would influence the dietary need of whey permeate during 7 to 11 kg BW of pigs. This study aimed to evaluate if weaning ages would affect the dietary needs of whey permeate for optimum growth performance of pigs at 7 to 11 kg BW. Methods A total of 1,632 pigs were weaned at d 21 (d 21.2 ± 1.3) or d 25 (d 24.6 ± 1.1) after birth. All pigs had a common early-weaner feeds until they reached 7 kg BW. When pigs reached 7 kg BW within a weaning age group, they were allotted in a randomized complete block design (2 × 4 factorial). Two factors were weaning age groups (21 and 25 d of age) and varying whey permeate levels (7.50%, 11.25%, 15.00%, and 18.75%). Data were analyzed using the GLM and NLIN procedures of SAS for slope-ratio and broken-line analyses to determine the growth response to whey permeate and optimal daily whey permeate intake for the growth of the pigs weaned at different ages. Results Pigs weaned at 21 d of age had a common diet for 11 d to reach 7 kg BW whereas pigs weaned at 25 d of age needed 2 d. The G:F of pigs weaned at 25 d of age responded to increased daily whey permeate intake greater (P < 0.05) than pigs weaned at 21 d of age. Breakpoints were obtained (P < 0.05) at 88 and 60 g/d daily whey permeate intake or 17.0% and 14.4% of whey permeate for G:F of pigs weaned at 21 and 25 d of age, respectively. Conclusion Pigs weaned at an older age with a short early-weaner phase had a greater growth response to whey permeate intake compared with pigs weaned at a younger age with a long early-weaner phase. Altering weaning ages affected dietary needs of whey permeate for optimum growth performance of pigs from 7 to 11 kg BW.

Isolation and determination of bacterial microbiota of Varroa destructor and isolation of Lysinibacillus sp. from it

Background The importance of bees for environmental health is known. Within the scope of this importance, it is of great importance to protect the health of bees and to prevent colony extinction. In this context, it is very important to develop effective methods in combating microorganisms, parasitoids, mites and organisms that cause disease or harm in bees. Both use different methods in terms of bee health. Result In this study, the possibility of the bacteria isolated from Varroa destructor mite being bioinsecticide was investigated. Accordingly, six bacteria were isolated from the mite. Isolated bacteria were analyzed according to biochemical tests, molecular analysis, optimum growth pH and phylogenetic tree drawn as Pantoea dispersa (GV1), Lysinibacillus macroides (GV3), Bacillus mycoides (GV4), Lysinibacillus fusiformis (GV5), Pseodomonas lutea (GV5), Lysinibacillus varians (GV7). Lysinibacillus sp. The entomopathogenic feature of Lysinibacillus sp. ranked it as the most important species. When the insecticidal properties of bacteria were examined, they were determined as 53, 90, 62, 95, 74 and 83% for GV1, GV3, GV4, GV5, GV6 and GV7, respectively. Conclusion Based on these results and literature review, Lysinibacillus sp. species had a high potential to be used as bioinsecticide against V. destructor mite.

First report of Diplodia seriata, D. mutila, and Dothiorella omnivora associated with apple cankers and dieback in Rio Negro, Argentina

Apple (Malus domestica Borkh.) is an important fruit crop in Río Negro, Argentina. In recent years, the frequency of canker and dieback symptoms have increased affecting different apple cultivars. In September 2014, a higher occurrence of cankers (29%) and dieback (9%) was observed in a commercial orchard of 10-year-old apple trees (n=210) cv ʻItal Redʼ in General Roca, Río Negro, Argentina (39°2'36.73"S – 67°32'44.55"W). Symptoms initially appeared as necrotic bark lesions on tree trunks and branches often associated with pruning wounds. Superficially, papyrus detachment of the bark and cracked bark were observed on the affected area. When the bark was removed, the diseased wood showed dark brown color. Cross sections of diseased branches revealed necrotic lesions that progress to branch death. Samples were collected from different symptomatic trees (n=30) and were superficially disinfected with 70% ethanol. Internal tissues (0.5 cm2) were excised from the advance margin of the necrotic lesions, plated on potato dextrose agar (PDA), and incubated at 22°C. Pycnidia were induced on sterilised pine needles overlaid on 2% water agar under near-UV light. Optimum temperature of culture growth on PDA was studied. According to their morpho-cultural characteristics, three different morphotypes were identified. The first, showed optimum growth at 30°C, had moderately dense white aerial mycelia and turned dark gray after 7 d. Conidia were ovoid, mostly aseptate, 20.8-25.6 × 8-11.4 µm (n=50) and hyaline to brown. The second, exhibited optimum growth from 25 to 30°C, was white to gray, with sparse to moderate aerial mycelium that turned dark olive green. Conidia were ovoid, 1-septate, 17.6-22.4 × 8.1-11.2 µm (n=50) and brown. Finally, the third showed optimum growth at 25°C, mycelium was grey to dark olive green. Conidia were oblong to ovoid with both ends rounded, aseptate and 1-septate at maturity, 20.8-24 × 11.2-14.4 µm (n=50), hyaline turned brown. Genomic DNA was extracted from one representative isolate of each morphotype and the ITS and EF1-α loci were amplified with the primer sets ITS1/ITS4 (White et al., 1990) and EF1-728F/EF1-986R (Carbone and Kohn, 1999), respectively. The nucleotide sequences indicated ≥99% identity to D. seriata (CBS 114796 and CBS 112555), D. mutila (CBS 302.36 and CBS 112553), and D. juglandis (CBS 188.87), reclassified as Dothiorella omnivora (Linaldeddu et al., 2016), for both DNA regions. The sequences were deposited in the GenBank database (MW596418, MW598375; MH665432, MK955889; MH665413, MK937229). To confirm pathogenicity, healthy 1-year-old twigs of adult apple trees were pruned and wounds of attached twigs immediately inoculated with 20 μL of conidial suspension (103 conidia.mL-1, n=9 per isolate) or sterile distilled water (control, n=9), and wrapped with Parafilm. The experimental design was randomized, and the experiment was repeated once. After 90 d, the area of lesion on all twigs inoculated was determined. D. mutila and Do. omnivora produced mean canker areas (65 and 73 mm2, respectively) significantly larger (p < 0.005) than D. seriata (48 mm2). No lesion occurred in the negative controls. Fulfilling Koch’s postulates, fungi were reisolated from all inoculated twigs and no fungus was recovered from controls. To our knowledge, this is the first report of D. seriata, D. mutila, and Do. omnivora associated with apple canker and dieback in Argentina, which shows the need of study the role of these fungi in orchard health.

Evaluation of the Properties of the DNA Methyltransferase from Aeropyrum pernix K1

In general, thermophilic bacteria with optimum growth temperatures over or equal to 60°C have been predicted to include only N 4 -methylcytosine or N 6 -methyladenine as methylated bases in their DNA, because 5-methylcytosine is susceptible to deamination by heat. However, from this study, A. pernix K1, with an optimum growth temperature at 95°C, was demonstrated to produce a DNA (cytosine-5)-methyltransferase.

Effects of Environmental factors on the Growth and Proliferation of Yeasts

Yeast is one of the organisms that grow and survive in diverse conditions. The influence of environmental factors on its growth and proliferation were evaluated. The yeast used for the study was isolated from honey using Sabouraud Dextrose Agar and pour plate methods. The effects of temperature, pH and ultraviolet radiation on the growth of Rhodotorula, Debaryomyces, Zygosaccharomyces and Candida species were determined using standard methods. The growths of all the yeast isolates were greatly affected at 80oC. Rhodotorulla species showed least growth at 50oC, but optimal growth was recorded at 30oC after 96 h of incubation. A similar trend was observed in Debaromyces species. Zygosaccharomyces species recorded high reduction in growth at 60oC after 96 h of incubation, though there were no significant differences in the growths of the isolates at 60oC and 80oC. Candida species recorded the least effect of temperature at 30oC and highest at 60oC and 80oC after 96 h of incubation. The results of the effect of pH on growth of the yeasts showed that Rhodotorula and Zygosaccharomyces had optimum growth at pH of 5 and 4 respectively. All the isolates showed increase in growth with increase in incubation time. Exposure of the isolates to UV-rays negatively affected the growths of the isolates. The growths of the yeasts decreased with increase in exposure time. This study showed that yeast can survive adverse temperature and pH and can as well survive UV-ray exposure.

Sustainable Repairing and Improvement of Concrete Properties Using Bacterial Consortium Isolated From Egypt

The small cracks in concrete constructions are inevitable due to deterioration during their service life throughout different load combination factors. In this study, we aimed to isolate, identify, and construct a bacterial consortium able to heal small cracks of concrete and enhance the different properties of concrete. Six isolates of bacillus, endospore-forming bacteria were isolated. There are only three isolates out of the six coded as NW-1, MK and NW-9 were showed the ability to produce urease enzyme and able to grow at 60°C with optimum growth at a temperature of 40°C. These isolates were survived in high pH, where isolate NW-1 was tolerated pH up to 11 with optimum growth at 10 while the isolates NW-9 and MK showed growth at pH 12 with an ideal growth at 10. CaCO3 production was observed by the three bacterial isolates whether in pure or mixed cultures (bacterial consortium) but the consortium consisting of MK and NW-9 was significantly the highest in productivity among them. Therefore, these two isolates were identified using 16s as Bacillus flexus MK-FYT-3 and Bacillus haynesii MK-NW-9 and deposited to GenBank under accession numbers MN965692 and MN965693 respectively. The effect of bacteria on some properties of concrete was studied, and the results showed that the compressive and tensile strengths of bio-concrete specimens were significantly increased by 31.29, 29 % after 7 days and 36.3, 39 % after 28 days of curing compared to control specimens. The results of permeability indicated that the bio-concrete specimens significantly showed less permeability than the control specimens by 21.1, 23.1% after 7 and 28 of curing, respectively. To determine the concrete density, Ultrasonic Pulse Velocity (UPV) test was performed, and the bio-concrete specimens gave higher values ​​than control specimens by 26 and 20% after curing for 7 and 28 days, respectively. Also, surface healing of concrete was observed visually, the bio-concrete showed white precipitates around and inside the cracks after 7 days, which led to almost complete sealing of concrete after 28 days of curing, while the control samples were showed only very slight deposits on the surface and away from the cracks. The micro-analysis of concrete samples using SEM and XRD were done. It was found that the bio-concrete specimens showed crystalline precipitate with different shapes under SEM, while no such deposits appeared in the control specimens. On the other hand, the XRD profile was explained the characteristic peaks of calcium carbonate in both the bio-concrete and the control specimens, but the peak intensity was higher in the bio-concrete than the control specimens. This reflects the effectiveness of bacterial consortium in repairing and preventing the concrete cracks from spreading in addition to improving the various properties of concrete leading to increasing its life and sustainability.