Evaluation of the secondary structure of poly-γ-glutamic acid produced by Bacillus subtilis EGP5QL12 by circular dichroism spectroscopy method

An extracellular polymer was isolated from the culture liquid of Bacillus subtilis EGP5QL12 with the yield of 5,6 g/L. On the basis of the data of thin layer chromatography, colorimetric analyses and FTIR spectroscopy, it was established that the polymer is poly-γ- glutamic acid (PGA). PGA is widely used in medicine, cosmetology and the food industry due to its ability to bind water and metal ions. To assess the biotechnological potential of the isolated polymer and predict the possibilities of its application in various fields of the national economy, it is necessary to analyze the characteristic spectral features that make it possible to establish its secondary structure. The isolated PGA preparation was analyzed by circular dichroism spectroscopy at various pH values. According to the results of this study, it was found that the polymer forms predominantly β-structures with a low proportion of irregular structures and α-helices, which gives it a high potential for creating hydrogels and composite materials.

Effects of ibuprofen and tetracyline on extracellular polymer production

Extracellular polymer substances (EPS) comprised of proteins, carbohydrates, and other biomolecules, are important for microbiological communities. The EPS provides benefits to wastewater treatment communities (WWTC) such as antibiotic resistance, and community structure. Therefore EPS can be viewed as a valuable health marker of WWTC and therefore it is important to determine effects of contaminants entering wastewater treatment plants (WWTPs) on EPS. WWTC were exposed to the non‐steroidal anti‐inflammatory drug (NSAID) Ibuprofen at 16 ng/mL and 100 ng/mL, and the antibiotic tetracycline at 50 ng/mL to determine how EPS and growth were affected. EPS was analyzed using high performance liquid chromatography (HPLC), Bradford protein analysis, and Anthrone carbohydrate analysis. It was determined that EPS content was lower at both Ibuprofen concentrations, enhanced with tetracycline, and comparable to control when both were present. Changes could not be linked to protein or carbohydrate concentration. Growth inhibition occurred in the presence of both drugs but not each individually, suggesting that Ibuprofen may increase tetracycline sensitivity through EPS inhibition.

Effects of ibuprofen and tetracyline on extracellular polymer production

Extracellular polymer substances (EPS) comprised of proteins, carbohydrates, and other biomolecules, are important for microbiological communities. The EPS provides benefits to wastewater treatment communities (WWTC) such as antibiotic resistance, and community structure. Therefore EPS can be viewed as a valuable health marker of WWTC and therefore it is important to determine effects of contaminants entering wastewater treatment plants (WWTPs) on EPS. WWTC were exposed to the non‐steroidal anti‐inflammatory drug (NSAID) Ibuprofen at 16 ng/mL and 100 ng/mL, and the antibiotic tetracycline at 50 ng/mL to determine how EPS and growth were affected. EPS was analyzed using high performance liquid chromatography (HPLC), Bradford protein analysis, and Anthrone carbohydrate analysis. It was determined that EPS content was lower at both Ibuprofen concentrations, enhanced with tetracycline, and comparable to control when both were present. Changes could not be linked to protein or carbohydrate concentration. Growth inhibition occurred in the presence of both drugs but not each individually, suggesting that Ibuprofen may increase tetracycline sensitivity through EPS inhibition.

Influence of behavioral and dietary aspects on children's oral health

The purpose of this study was to verify the association of microbiological aspects, behavioral and eating habits that affect the oral health of preschoolers. This is a cross-section of a longitudinal study, with a sample of 42 preschoolers at 30 months of age. A home visit was carried out to conduct an interview on aspects of breastfeeding, early weaning, the child's oral hygiene habits, such as brushing frequency and habits, sharing toothbrushes and kitchen utensils and 24-hour food recall of the preschooler. Was collected 0.5 ml of saliva from the oral floor of the mother and the preschooler using sterile disposable pipettes for culture in a Petri dish. It was observed that there was an association between early weaning (p = 0.046) and bottle use (p = 0.018) with the presence of caries; however, there was no association between the consumption of sugary foods between meals (p = 0.302). The average colony-forming unit (CFU) / ml of S. mutans found in the mothers' saliva was 974421 and the preschool was 135341.9. Extracellular polymer was found in the CFU of samples from 61.90% of mothers and 09.52% of preschoolers. Eating habits such as early weaning and bottle use were associated with the presence of caries. There was no association between microbiological and behavioral aspects that affect oral health and the consumption of sugary foods between meals with the presence of caries in preschoolers.

Effect of organic loading on phosphorus forms transformation and microbial community in continuous-flow A2/O process

A continuous-flow Anaerobic/Anoxic/Oxic (A2/O) system was operated at different organic concentrations to systematically investigate the effect on the nutrient removal, secretion characteristics of extracellular polymer, phosphorus forms transformation and changes in functional flora in this system. The results showed that high organic loading was more conducive to promote the secretion of extracellular polymeric substance (EPS), the increase of polysaccharide content was more obvious compared with protein, the impact of organic loading on the components of loosely-bound EPS (LB-EPS) was higher than that of tight-bound EPS (TB-EPS). Phosphorus in sludge floc mainly existed in the form of inorganic phosphorus (IP), and IP mainly existed in the form of apatite inorganic phosphorus (AP). High organic load showed higher phosphorus storage in EPS, and the phosphorus content in EPS was positively correlated with the content of EPS. Non-apatite phosphorus (NAIP) content played an important role in the extracellular dephosphorization. The abundance of Nitrosomonas and Nitrospira responsible for nitrification decreased with the increase of organic loading. The group of denitrifiers was large, and Azospira was the most abundant genus among them. Dechloromonas, Acinetobacter, Povalibacter, Chryseolinea and Pirellula were the functional genera closely associated with phosphorus removal.

Recent Advances and Applications of Bacterial Cellulose in Biomedicine

Bacterial cellulose (BC) is an extracellular polymer produced by Komagateibacter xylinus, which has been shown to possess a multitude of properties, which makes it innately useful as a next-generation biopolymer. The structure of BC is comprised of glucose monomer units polymerised by cellulose synthase in β-1-4 glucan chains which form uniaxially orientated BC fibril bundles which measure 3–8 nm in diameter. BC is chemically identical to vegetal cellulose. However, when BC is compared with other natural or synthetic analogues, it shows a much higher performance in biomedical applications, potable treatment, nano-filters and functional applications. The main reason for this superiority is due to the high level of chemical purity, nano-fibrillar matrix and crystallinity. Upon using BC as a carrier or scaffold with other materials, unique and novel characteristics can be observed, which are all relatable to the features of BC. These properties, which include high tensile strength, high water holding capabilities and microfibrillar matrices, coupled with the overall physicochemical assets of bacterial cellulose makes it an ideal candidate for further scientific research into biopolymer development. This review thoroughly explores several areas in which BC is being investigated, ranging from biomedical applications to electronic applications, with a focus on the use as a next-generation wound dressing. The purpose of this review is to consolidate and discuss the most recent advancements in the applications of bacterial cellulose, primarily in biomedicine, but also in biotechnology.