Antimicrobial Resistance of Acetobacter and Komagataeibacter Species Originating from Vinegars

Consumers’ preference towards healthy and novel foods dictates the production of organic unfiltered bottled vinegar that still contains acetic acid bacteria. After ingesting vinegar, the bacteria come into close contact with the human microbiota, creating the possibility of horizontal gene transfer, including genetic determinants for antibiotic resistance. Due to the global spread of antimicrobial resistance (AMR), we analyzed the AMR of Acetobacter and Komagataeibacter species originating mainly from vinegars. Six antibiotics from different structural groups and mechanisms of action were selected for testing. The AMR was assessed with the disk diffusion method using various growth media. Although the number of resistant strains differed among the growth media, 97.4%, 74.4%, 56.4%, and 33.3% of strains were resistant to trimethoprim, erythromycin, ciprofloxacin, and chloramphenicol, respectively, on all three media. Moreover, 17.9% and 53.8% of all strains were resistant to four and three antibiotics of different antimicrobial classes, respectively. We then looked for antimicrobial resistance genes in the genome sequences of the reference strains. The most common genetic determinant potentially involved in AMR encodes an efflux pump. Since these genes pass through the gastrointestinal tract and may be transferred to human microbiota, further experiments are needed to analyze the probability of this scenario in more detail.

Microorganism growth profiles during fermentation of Gayo Arabica wine coffee

Coffee is a non-alcoholic beverage that is consumed globally due to its specific flavour and functional properties. Nowadays coffee is diversified based on its coffee varieties, brewing methods, and bean processing techniques. Wine coffee is a commercial name for fermented coffee, a new coffee diversification product. Wine coffee is produced by fermenting coffee cherries for 30 to 60 days. As a new product, the process is not well studied. This research aims to explore the microorganisms’ activity and its profile growth during 30 days of fermentation. The documentation of pH and temperature, and microbial sampling during coffee cherry fermentation were conducted seven times, started at 0 days; 2 days; 4 days; 6 days; 8 days; 10 days; 12 days; 14 days; 16 days; 20 and 30 days. The results showed that pH decreases and temperature increases during fermentation. pH started from 5.0 and down to 3.9 when fermentation is terminated after 30 days, whilst the temperature slightly changes from 25°C to 30°C. The microorganism’s population shows the presence of yeast, lactic acid (LAB) and acetic acid bacteria (AAB) in wine coffee production. The yeast population increases in the mid fermentation as the cherries are damaged and provide suitable nutrition for the yeast. LAB also co-exists at a similar stage. Further research should be done, especially to understand the interaction mechanism between yeast and yeast, yeast and LAB, and yeast and AAB.

Prevalence and Recovery of Microorganisms from Containers used for the Collection of Forensic Biological Samples

Background: Microbes play a significant role in the degradation of biological evidence collected for forensic analysis. The present study is aimed to isolate and identify the microbes present inside the empty container used for the biological evidence collection. Methods: Bacterial isolation from the selected containers was done by cotton swab over the inner surface of the containers. Streaking was done on the surface of the three different culture plates as a Blood agar plate, Nutrient plate and MacConkey plate. The plates were placed in an incubator shaker at 37ºC for 48 hours. The colonies grown on the surface of the media were counted on and used for further study. Various biochemical assays were performed to characterize isolated bacteria. Results: Staining results suggested that the presence of Gram-positive stain (Staphylococcus, Bacillus, Corynebacterium, Clostridium) and Gram negative stain (E. coli, Enterobacteriaceae, Pseudomonas, Salmonella, Shigella, Stenotrophomonas, Bdellovibrio, Acetic acid bacteria). The Catalase and Coagulase test suggested the presence of Staphylococcus aureus, S. epidermis and S. sapropyticus. Moreover, the indole test suggested the presence of Citrobacter koseri, Kebsiella oxytoca, Proteus vulgaris etc. Some of the bacteria were urea metabolizing, including Proteus spp, Helicobacter pylori, Cryptococcus spp, Corynebacterium spp. Conclusion: This study recommends that there should be proper maintenance of the chain of custody from the collection to analysis so that evidence properly prevents degradation or contamination in the biological evidence. Extra care is needed for the collection and packing of biological evidence from the crime scene. Moreover, the collection containers, if left wide open, lead to contamination and degradation of biological evidence.

Investigation of Antiproliferative Effects of Home-Made and Commercial Apple Vinegars on Myeloma Cells

Vinegar is an aqueous food product made by a succession of yeast and acetic acid bacteria activities from fruits that contain high carbohydrates such as apples and grapes. Vinegar has been used as a dietary spice and natural remedy since ancient times due to its therapeutic properties including antimicrobial, antidiabetic, and anticancer activities. It has been shown that some bioactive compounds exhibiting antioxidant activity in vinegars lead to anticancer activity. The aim of the present study was to investigate antiproliferative effect of commercial and home-made apple vinegars in native and neutralized form on myeloma cells. In order to neutralize the vinegars, sodium hydroxide (NaOH) was used. A serial two-fold dilutions of the vinegars (50%, 25%, 12.5%, 6.25%, 3.12%, 1.56%, 0.78%, 0.39%) prepared with cell medium were treated to the cells. The MTT (3-(4.5-Dimethylthiazol-2-yl)-2.5-Diphenyltetrazolium Bromide) assay was used to determine the cellular viability in the cells treated with the vinegars. In this study, while commercial vinegar possessed a stronger antiproliferative activity than home-made vinegar, all native vinegars possessed stronger antiproliferative effect than neutralized vinegars. Interestingly, when home-made vinegar (both native and neutralized) concentrations were from 6.25 to 1.56%, the cell viability increased. Apple vinegar exhibited antiproliferative activity on myeloma cells; however, further studies are required to clarify the mechanisms underlying this activity.

Vinegar Production from Corinthian Currants Finishing Side-Stream: Development and Comparison of Methods Based on Immobilized Acetic Acid Bacteria

Fruit wastes and side-streams can be used for vinegar production to create added value for the agri-food sector and enhance farmer incomes and local economies. In this study, methods for vinegar production by wild and selected acetic acid bacteria (the quick starter Acetobacter aceti and the acid-resistant Komagataeibacter europaeus), free (FC) and immobilized (IC) on a natural cellulosic carrier, are proposed using sweet wine made from the industrial finishing side-stream (FSS) of Corinthian currants as raw material. The results showed all cultures can produce vinegar with 46.65 ± 5.43 g/L acidity, from sweet FSS wine containing 5.08 ± 1.19% alcohol. The effect of immobilization was more obvious in the case of the selected culture, presenting better acetification efficiency, both fresh and after cold storage for 2 months. The vinegars had an antioxidant capacity of 263.5 ± 8.4 and 277.1 ± 6.7 mg/L (as ascorbic acid) and phenolic content 333.1 ± 12.0 and 222.2 ± 2.9 mg/L (as gallic acid) (for FC and IC, respectively). They also had a rich volatilome (140 compounds identified by SPME GC-MS), with higher percentages of esters identified in vinegars made by IC. The results are encouraging for vinegar production with IC of a mixed A. aceti and K. europaeus culture.

Bacterial Cellulose Production from Acerola Industrial Waste Using Isolated Kombucha Strain

Bacterial Cellulose (BC) production is still considered expensive and challenging for industries. Herein, BC was produced through an acetic acid bacteria isolated from the kombucha consortium and an extract from acerola juice-industrial waste. The isolated bacterium was characterized through different assays (biochemical characterization and 16S rRNA gene) being identified as Komagataeibacter rhaeticus. BC production with static cultivation mode by the isolated strain was compared using traditional Hestrin-Schramm (HS) medium and acerola waste (AC) (5% w/v). The kinetic behavior of BC production was slightly higher in the HS medium reaching 2.9 g/L after 12 days of fermentation, while 2.3 g/L in the AC medium. Minor differences were observed between crystallite size and d-spacing, highlighting BC produced by the AC medium with higher crystallinity of 93.9% and two-fold breaking stress resistance in comparison with the conventional medium, with high-temperature stability and economically feasible, promissory results for further application of this synthetized cellulose obtained from industrial residues.

Preparation of Tubular Biocellulose Implants and Its Use in Surgery—A Review

This review highlights the current state regarding the preparation and characterization of tubular biocellulose materials as well as their application and application potential with a special focus on abdominal oncologic surgery. Biocellulose is a natural polymer synthesized by acetic acid bacteria from low molecular sugars and alcohols as a mechanically stable nanofiber network at the interface between the aqueous culture medium and air. This hydrogel is characterized by very high purity and biocompatibility, dimensional stability, and good surgical handling. With this property profile, biocellulose proves to be a promising candidate for the development of novel medical soft tissue implants. This requires close R&D cooperation between chemists, material scientists, biotechnologists, and surgeons. In this sense, this review spans from the natural polymer to the design of biocellulose implants and surgical suitability. It is also a concern of this article to show concretely the great need for such implants and the fields of application in oncological abdominal surgery where tubular biocellulose is or could be the focus of research. Furthermore, a critical assessment for the use of biocellulose materials concerning incidence malignancy and surgical interventions, complication rates, and current studies is emphasized. The regeneration of damaged bile ducts by the use of biocellulose implants is a first example.