Green alternatives to petroleum-based plastics: production of bioplastic from Pseudomonas neustonica strain NGB15 using waste carbon source.

Polyhydroxyalkanoates have attracted great interest as a suitable alternative to petrochemical based plastics due to their outstanding properties such as biodegradability and biocompatibility. However, the biggest problem in the production of microbial polyhydroxyalkanoates is low cost-effectiveness. In this study, polyhydroxyalkanoate production was carried out using waste substrates with local isolates. Culture conditions were optimized to increase the polyhydroxyalkanoate production potential. The produced polyhydroxyalkanoate was characterized by FTIR analyses, and its metabolic pathway was determined by real-time PCR. According to the results, the best polyhydroxyalkanoate producer bacteria was characterized as Pseudomonas neustonica NGB15. The optimal culture conditions were detected as 30 g/L banana peel powder, 25 °C temperature, pH 8, and 4-day incubation time. Under the optimized conditions, 3.34 g/L PHA production was achieved. As a result of FTIR analyses, major peaks were obtained at 1723, 1277, 1261, 1097, 1054, and 993 cm-1. These peaks represent that the type of produced polyhydroxyalkanoate was poly-ß-hydroxybutyrate. According to gene expression profile of NGB15, it was determined that Pseudomonas neustonica NGB15 produces PHA using the de novo fatty acid synthesis metabolic pathway. In conclusion, poly-ß-hydroxybutyrate production by Pseudomonas neustonica NGB15 using a low-cost fermentation medium has been shown to be biotechnologically promising.

Determination of foodborne pathogens in minced beef by real-time PCR without culture enrichment.

Meat provides the necessary environment for the growth of foodborne pathogens due to its features such as being rich in protein and having sufficient water activity. Listeria monocytogenes, Salmonella enterica, and Escherichia coli O157:H7, which can be transmitted through many foods, including water, and cause serious diseases, are among the significant pathogens. In the current study. Detection of Listeria monocytogenes, Escherichia coli and Salmonella enterica in 100 minced beef samples collected from different butchers and markets situated in the central districts of Erzurum province was performed by Real-Time PCR without pre-enrichment and DNA isolation. Linear regression equations of Ct values of standard pathogenic bacteria were created. Ct values of minced beef samples obtained as a result of Real-Time PCR analysis were substituted in the equations, and the amounts of pathogenic bacteria in the samples were determined. Listeria monocytogenes, Escherichia coli, and Salmonella enterica were detected in 45, 30, and 29 of 100 minced beef samples, respectively. It is known that the Real-Time PCR method, which is used to detect pathogenic bacteria, is more specific, fast, and reliable than conventional methods. According to the results obtained, it has been clearly observed that with our new approach, pathogenic bacteria growing on foods can be detected sensitively with less cost, shorter amount of time, and minimized workload without pre-enrichment and DNA isolation.

Anoxybacillus: an overview of a versatile genus with recent biotechnological applications.

The Bacillaceae family members are considered to be a good source of microbial factories for biotechnological processes. In contrast to Bacillus and Geobacillus, Anoxybacillus, which would be thermophilic and spore-forming group of bacteria, is a relatively new genus firstly proposed in the year of 2000. The development of thermostable microbial enzymes, waste management and bioremediation processes would be a crucial parameter in the industrial sectors. There has been increasing interest in Anoxybacillus strains for biotechnological applications. Therefore, various Anoxybacillus strains isolated from different habitats have been explored and identified for biotechnological and industrial purposes such as enzyme production, bioremediation and biodegradation of toxic compounds. Certain strains have ability to produce exopolysaccharides possessing biological activities including antimicrobial, antioxidant and anticancer. This current review provides past and recent discoveries regarding Anoxybacillus strains and their potential biotechnological applications in enzyme industry, environmental processes and medicine.

Purification and biochemical characterization of a new thermostable laccase from Enterococcus faecium A2 by a three-phase partitioning method and investigation of its decolorization potential.

Three-phase partitioning (TPP) is a simple, fast, cost-effective, and highly efficient process that can be used in the purification of laccases. In this study, microorganisms with laccase activity were isolated from water samples collected from the Agri-Diyadin hot spring. The isolate with the highest laccase activity was found to be the A2 strain. As a result of molecular (16S rRNA sequence) and conventional (morphological, biochemical, and physiological) analyses, it was determined that the A2 isolate was 99% similar to Enterococcus faecium (Genbank number: MH424896). The laccase was purified to 4.9-fold with 110% recovery using the TPP. The molecular mass of the enzyme was found by SDS-PAGE to be 50.11 kDa. Optimum pH 6.0 and optimum temperature for laccase were determined as 80 °C. The laccase exhibited pH stability over a wide range (pH 3.0-9.0) and a high thermostability, retaining over 90% of its activity after 1 h of incubation at 20-90 °C. The laccase exhibited high thermostability, with a heat inactivation half-life of approximately 24 h at 80 °C. The enzyme remained highly stable in the presence of surfactants and increased its activity in the presence of organic solvents, Cr2+, Cu2+, and Ag+ metal ions. The Km, Vmax, kcat, and kcat/Km values of laccase for 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) substrate were 0.68 mM, 5.29 µmol mL-1 min-1, 110.2 s-1, and 162.1 s-1 mM-1, respectively.

Preparation of chitosan from waste shrimp shells fermented with Paenibacillus jamilae BAT1.

In this study, chitin extraction from shrimp shell powder (SSP) using locally isolated Paenibacillus jamilae BAT1 (GenBank: MN176658), the preparation of chitosan from the extracted chitin, and the characterization and biological activity (antimicrobial and antioxidant) of the prepared chitosan (PC) were investigated. It was determined that P. jamilae BAT1 did not have chitinase activity but showed high protease activity and protein removal potential. Optimum pH, shell concentration and incubation time for deproteinization were determined as 7.0, 60 g/L and 4 days, respectively. Addition of KH2PO4 or MgSO4 did not affect chitin extraction and deproteinization yield. The maximum yields of deproteinization, demineralization and chitin extraction yields were 87.67, 41.95 and 24.5%, respectively. The viscosity-average molecular weight of PC was determined as 1.41 × 105 g/mol. The deacetylation degree of PC (86%) was found to be higher that of commercial chitosan (CC) (78%). DPPH scavenging activity of PC (IC50 0.59 mg/mL) was higher than that of CC (IC50 3.72 mg/mL). PC was found to have higher antimicrobial activity against the bacteria E. coli and S. aureus and the yeast C. albicans when compared to CC. This is the first study on the use of the bacterium P. jamilae in biological chitin extraction.

Effect of final irrigation with sodium hypochlorite at different temperatures on postoperative pain level and antibacterial activity: a randomized controlled clinical study.

OBJECTIVE: To evaluate the effect of final irrigation of root canals with NaOCl solution at different temperatures on postoperative pain level and antimicrobial activity. METHODOLOGY: 45 patients were randomly divided into three groups using a web program according to the irrigation selected: NaOCl 2ºC, NaOCl 25ºC and NaOCl 45ºC. First root canal samples were collected before treatment (S1). After chemo-mechanical preparation, final irrigation was performed with the selected irrigant (NaOCl 2ºC, NaOCl 25ºC and NaOCl 45ºC) and second samples were collected (S2). Samples were subjected to quantitative real-time polymerase chain reaction to evaluate the levels of total bacteria. The root canal treatments were completed and the participants were given instructions to record postoperative pain levels at 24, 48 and 72 hours, 5 days and 1 week after treatment using a visual analog scale (VAS). RESULTS: The reduction in the number of total bacterial cell equivalents from S1 to S2 was statistically significant in all groups (p<0.001). The NaOCl 2˚C group reported significantly less postoperative pain than the NaOCl 45˚C group (p<0.05). Postoperative analgesic intake was significantly higher in the NaOCl 45˚C group than in the NaOCl 2˚C group (p<0.05). CONCLUSION: We conclude that final irrigation with NaOCl at different temperatures results in similar antibacterial effectiveness. Final irrigation with cold NaOCl (2˚C) is better than NaOCl 45˚C when comparing postoperative pain levels.

Effect of final irrigation with sodium hypochlorite at different temperatures on postoperative pain level and antibacterial activity: a randomized controlled clinical study

Abstract Objective To evaluate the effect of final irrigation of root canals with NaOCl solution at different temperatures on postoperative pain level and antimicrobial activity. Methodology 45 patients were randomly divided into three groups using a web program according to the irrigation selected: NaOCl 2ºC, NaOCl 25ºC and NaOCl 45ºC. First root canal samples were collected before treatment (S1). After chemo-mechanical preparation, final irrigation was performed with the selected irrigant (NaOCl 2ºC, NaOCl 25ºC and NaOCl 45ºC) and second samples were collected (S2). Samples were subjected to quantitative real-time polymerase chain reaction to evaluate the levels of total bacteria. The root canal treatments were completed and the participants were given instructions to record postoperative pain levels at 24, 48 and 72 hours, 5 days and 1 week after treatment using a visual analog scale (VAS). Results The reduction in the number of total bacterial cell equivalents from S1 to S2 was statistically significant in all groups (p<0.001). The NaOCl 2˚C group reported significantly less postoperative pain than the NaOCl 45˚C group (p<0.05). Postoperative analgesic intake was significantly higher in the NaOCl 45˚C group than in the NaOCl 2˚C group (p<0.05). Conclusion We conclude that final irrigation with NaOCl at different temperatures results in similar antibacterial effectiveness. Final irrigation with cold NaOCl (2˚C) is better than NaOCl 45˚C when comparing postoperative pain levels.

Genome-based classification of Calidifontibacillus erzurumensis gen. nov., sp. nov., isolated from a hot spring in Turkey, with reclassification of Bacillus azotoformans as Calidifontibacillus azotoformans comb. nov. and Bacillus oryziterrae as Calidifontibacillus oryziterrae comb. nov.

A novel Gram-stain-positive, rod-shaped, endospore-forming, motile, aerobic bacterium, designated as P2T, was isolated from a hot spring water sample collected from Ilica-Erzurum, Turkey. Phylogenetic analyses based on 16S rRNA gene sequence comparisons affiliated strain P2T with the genus Bacillus, and the strain showed the highest sequence identity to Bacillus azotoformans NBRC 15712T (96.7 %). However, the pairwise sequence comparisons of the 16S rRNA genes revealed that strain P2T shared only 94.7 % sequence identity with Bacillus subtilis subsp. subtilis NCIB 3610T, indicating that strain P2T might not be a member of the genus Bacillus. The digital DNA-DNA hybridization and average nucleotide identity values between strain P2T and B. azotoformans NBRC 15712T were 19.8 and 74.2 %, respectively. The cell-wall peptidoglycan of strain P2T contained meso-diaminopimelic acid. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an aminophospholipid, five unidentified phospholipids and two unidentified lipids while the predominant isoprenoid quinone was MK-7. The major fatty acids were iso-C15 : 0 and iso-C16 : 0. The draft genome of strain P2T was composed of 82 contigs and found to be 3.5 Mb with 36.1 mol% G+C content. The results of phylogenomic and phenotypic analyses revealed that strain P2T represents a novel genus in the family Bacillaceae, for which the name Calidifontibacillus erzurumensis gen. nov., sp. nov. is proposed. The type strain of Calidifontibacillus erzurumensis is P2T (=CECT 9886T=DSM 107530T=NCCB 100675T). Based on the results of the present study, it is also suggested that Bacillus azotoformans and Bacillus oryziterrae should be transferred to this novel genus as Calidifontibacillus azotoformans comb. nov. and Calidifontibacillus oryziterrae comb. nov., respectively.

Bacillus pasinlerensis sp. nov., a thermophilic bacterium isolated from a hot spring in Turkey.

A Gram-reaction-positive, endospore-forming bacterium, designated strain P1T, was isolated from water samples collected from Pasinler Hot Spring and characterized using a polyphasic approach to clarify its taxonomic position. Strain P1T was found to have chemotaxonomic and morphological characteristics consistent with its classification in the genus Bacillus. The strain shared the highest 16S rRNA gene sequence identity values with Bacillus thermolactis R-6488T (97.6 %) and Bacillus kokeshiiformis MO-04T (97.2 %) and formed a distinct clade with both type strains in the phylogenetic trees based on 16S rRNA gene sequences. Strain P1T could grow optimally at 55 °C and in the presence of 2 % NaCl. The organism was found to contain meso-diaminopimelic acid as the diagnostic diamino acid in the cell-wall peptidoglycan. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The predominant menaquinone was determined to be MK-7. The major cellular fatty acids were identified as iso-C15 : 0, iso-C17 : 0 and anteiso-C17 : 0. Based upon the consensus of phenotypic and phylogenetic analyses, strain P1T represents a novel species of the genus Bacillus, for which the name Bacillus pasinlerensis sp. nov. is proposed. The type strain is P1T (=DSM 107529T=CECT 9885T=NCCB 100674T).

Purification and biochemical characterization of a novel thermostable serine alkaline protease from Aeribacillus pallidus C10: a potential additive for detergents.

An extracellular thermostable alkaline serine protease enzyme from Aeribacillus pallidus C10 (GenBank No: KC333049), was purified 4.85 and 17. 32-fold with a yield of 26.9 and 19.56%, respectively, through DE52 anion exchange and Probond affinity chromatography. The molecular mass of the enzyme was determined through sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), with approximately 38.35 kDa. The enzyme exhibited optimum activity at pH 9 and at temperature 60 °C. It was determined that the enzyme had remained stable at the range of pH 7.0-10.0, and that it had preserved more than 80% of its activity at a broad temperature range (20-80 °C). The enzyme activity was found to retain more than 70% and 55% in the presence of organic solvents and commercial detergents, respectively. In addition, it was observed that the enzyme activity had increased in the presence of 5% SDS. KM and Vmax values were calculated as 0.197 mg/mL and 7.29 µmol.mL-1.min-1, respectively.

Thermotolerant alkaline protease enzyme from Bacillus licheniformis A10: purification, characterization, effects of surfactants and organic solvents.

In this study, the extracellular thermostable alkaline protease out of A10 strain was purified 1.38-fold with 9.44% efficiency through the ammonium sulfate precipitation-dialysis and DE52 anion exchange chromatography methods. The molecular weight of the enzyme in question along with sodium dodecyl sulfate-polyacrylamide gel electrophoresis was determined to be approximately 40.55 kDa, whereas the optimum pH and temperature ratings were identified as 9.0 and 70 °C, respectively. It was seen that the enzyme had remained stable between pH 7.5-10.5 range, protecting more than 90% of its activity in the wake of 1 h incubation at 60-70 °C. It was also observed that the enzyme enhanced its activity in the presence of Mg(2+), Mn(2+), K(+), while Fe(2+), Ni(2+), Zn(2+), Ag(+ )and Co(2+ ) decreased the activity. Ca(2+), however, did not cause any change in the activity. The enzyme was seen to have been totally inhibited by phenylmethylsulfonyl fluoride, therefore, proved to be a serine alkaline protease.