Identification of Bacillus spp. from Bikalga, fermented seeds of Hibiscus sabdariffa: phenotypic and genotypic characterization

Detergent-stable amylase production by Paenibacillus lactis strain OPSA3 isolated from soil; optimization by response surface methodology

This study aimed to isolate thermostable, alkaliphilic, and detergent-tolerant amylase-producing bacteria. Pure isolates from environmental samples were screened on a starch-based medium (pH 11), and selected isolates were identified using cultural and molecular techniques. Product optimization studies were conducted, and secreted amylase was partially purified using 40% (w/v) saturation ammonium sulfate at 4 °C. The wash performance of concentrated amylase was analyzed. A novel isolate, Paenibacillus lactis OPSA3, was selected for further studies. The isolate produced amylase optimally when grown on banana peels and soybean extracts, which are agro-wastes. Optimization by Response surface Methodology resulted in a 2.1-fold increase in alkaliphilic amylase production. A 2.46-fold purification was achieved, with an enzyme activity yield of 79.53% and specific activity of 26.19 Umg^-1. Wash performance analysis using the amylase supplemented with boiled commercial detergent (kiln®) showed good cleaning efficiency. The amylase has the potential for application as a component of green detergent.

Plant-Based Alkaline Fermented Foods as Sustainable Sources of Nutrients and Health-Promoting Bioactive Compounds

Traditional food fermentation is a practice that precedes human history. Acidic products such as yogurts and sourdoughs or alcoholic beverages produced through lactic acid or yeast fermentations, respectively, are widely described and documented. However, a relatively less popular group of fermented products known as alkaline fermented foods are common traditional products in Africa and Asia. These products are so called “alkaline” because the pH tends to increase during fermentation due to the formation of ammonia resulting from protein degradation by Bacillus species. Plant-based alkaline fermented foods (AFFs) are generally produced from legumes including soybean, non-soybean leguminous seeds, and other non-legume plant raw materials. Alkaline fermented food products such as natto, douchi, kinema, doenjang, chongkukjang, thua nao, meitauza, yandou, dawadawa/iru, ugba, kawal, okpehe, otiru, oso, ogiri, bikalga, maari/tayohounta, ntoba mbodi, cabuk, and owoh are produced at small industrial scale or household levels and widely consumed in Asia and Africa where they provide essential nutrients and health-promoting bioactive compounds for the population. Alkaline food fermentation is important for sustainable food security as it contributes to traditional dietary diversity, significantly reduces antinutritional components in raw plant materials thereby improving digestibility, improves health via the production of vitamins, and may confer probiotic and post-biotic effects onto consumers. In this review, we present currently available scientific information on plant-based AFFs and their role as sustainable sources of nutrients and bioactive compounds for improved health. Finally, we provide perspectives on research needs required to harness the full potential of AFFs in contributing to nutrition and health.

Probiotic Lactobacilli in Fermented Dairy Products: Selective Detection, Enumeration and Identification Scheme

A selection of 36 commercial probiotic fermented dairy products from UK and Europe markets were evaluated for the numbers, types, and viability of Lactobacillus strains against the stated information on their packages. A comparative study was carried out on selectivity of MRS-Clindamycin, MRS-Sorbitol, and MRS-IM Maltose, to select the right medium for enumeration of probiotic Lactobacillus. Based on selectivity of medium for recovery of the targeted lactobacilli, and also simplicity of preparation, MRS-Clindamycin was chosen as the best medium for enumeration of probiotic Lactobacillus in fermented milks. The results of enumeration of lactobacilli showed that 22 out of a total 36 tested products contained more than 10⁶ colony-forming units/g at the end of their shelf life, which comply with the recommended minimum therapeutic level for probiotics. Rep-PCR using primer GTG-5 was applied for initial discrimination of isolated strains, and isolates, which presented different band profile, were placed in different groups. The isolated Lactobacillus spp. were identified mainly as Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus paracasei by analysis of partial sequences of the 16S ribosomal RNA and rpoA genes.

Identification and characterisation of the lactic acid bacteria associated with the traditional fermentation of dairy fermented product

The aim of this research was to identify the key lactic acid bacteria associated with the fermentation of dairy traditional fermented products for developing starter cultures for controlled fermentation. A total of 100 lactic acid bacteria (LAB) were isolated from dairy traditional fermented products. Samples were obtained from eight producers in the South East of Nigeria. Isolates were identified by phenotypic and genotypic techniques including rep-PCR genotyping and sequencing of the 16S rRNA, pheS and rpoA genes. Isolates were characterised for antimicrobial activity against foodborne pathogens, exopolysaccharide (EPS) production and survival at low pH and in the presence of bile salts. All isolates clustered into 11 distinct rep-PCR groups and were identified as Lactobacillus fermentum (40%), Lactobacillus delbrueckii (23%), Streptococcus thermophilus (22%), Streptococcus infantarius (10%), Lactobacillus senioris (2%), Leuconostoc pseudomesenteriodes (2%) and Enterococcus thailandicus (1%). Lactobacillus fermentum showed a broad spectrum antimicrobial activity and survival at low pH, while Lactobacillus delbrueckii was able to tolerate low pH and produce EPS. All isolates survived in vitro exposure to 1% (w/v) bile salts over a 3-h period. L. fermentum, L. delbrueckii and S. thermophilus could be used to simulate the fermentation of dairy traditional fermented products.

Synergic Involvements of Microorganisms in the Biomedical Increase of Polyphenols and Flavonoids during the Fermentation of Ginger Juice

Steered fermentation by microorganisms gives great added value in the nutritional quality of local food. Ginger rhizome naturally contains a myriad of bioactive compounds including polyphenol and flavonoids. The aim of this work was to ferment the ginger juice, to evaluate the biochemical parameters of ginger wine, and to understand the involvement of microorganisms in the bioincrease of polyphenol compounds. Titratable acidity and pH values were determined and showed that pH is around 1.6 at the end of the fermentation when the acidity is around 6.431 g/L. Using colorimetric assay, the total polyphenolic and flavonoid compounds were evaluated throughout the fermentation. The variation of the polyphenol and flavonoid concentrations of the unsweetened sample was around 10.18 to 14.64 mg Eq AG/g and 1.394 to 2.224 mg Eq Cat/g Ms, but those from the sweet sample were around 10.82 to 18.34 mg Eq AG/g Ms and 1.311 to 2.290 mg Eq Cat/g. Using one-step PCR, multiplex techniques with specific primers, with yeast-like phenotype 27.27% (6), have been assigned among 22 isolates to Saccharomyces cerevisiae. By using PCR multiplex techniques, Bacillus licheniformis, Bacillus pumilus, Bacillus safensis, and Saccharomyces cerevisiae have been identified. Together with Saccharomyces cerevisiae, we showed that Bacillus sp. are able to secrete enzymatic landscape with some activities up to 50% including cellulase, amylase, pectinase, and protease.

Fermented foods in a global age: East meets West

Fermented foods and alcoholic beverages have long been an important part of the human diet in nearly every culture on every continent. These foods are often well-preserved and serve as stable and significant sources of proteins, vitamins, minerals, and other nutrients. Despite these common features, however, many differences exist with respect to substrates and products and the types of microbes involved in the manufacture of fermented foods and beverages produced globally. In this review, we describe these differences and consider the influence of geography and industrialization on fermented foods manufacture. Whereas fermented foods produced in Europe, North America, Australia, and New Zealand usually depend on defined starter cultures, those made in Asia and Africa often rely on spontaneous fermentation. Likewise, in developing countries, fermented foods are not often commercially produced on an industrial scale. Although many fermented products rely on autochthonous microbes present in the raw material, for other products, the introduction of starter culture technology has led to greater consistency, safety, and quality. The diversity and function of microbes present in a wide range of fermented foods can now be examined in detail using molecular and other omic approaches. The nutritional value of fermented foods is now well-appreciated, especially in resource-poor regions where yoghurt and other fermented foods can improve public health and provide opportunities for economic development. Manufacturers of fermented foods, whether small or large, should follow Good Manufacturing Practices and have sustainable development goals. Ultimately, preferences for fermented foods and beverages depend on dietary habits of consumers, as well as regional agricultural conditions and availability of resources.

Identification of spore-forming bacteria isolated from contaminated Lowenstein Jensen media and effectiveness of Vancomycin to reduce Mycobacterial culture contamination in Burkina-Faso

The type of commensal microorganisms can influence the efficiency of sputum decontamination for TB diagnosis. A basic characterization of contaminants from LJ contaminated media showed that Gram positive Spore Forming Bacteria (SFB) were the major contaminants. This study aims to identify the species of this contaminants and to evaluate the effectiveness of VCNT at 10 µg of vancomycin to reduce mycobacterial culture contamination mainly linked to SFB. Fifty-three SFB isolated between February 2016 and May 2017 were used. The effectiveness of LJ with VCNT at 10 µg of Vancomycin were evaluated with sputum collected in the same period. SFB had been stored at -20 °C and identified after subculture onto 5% sheep blood Columbia agar and incubated at 37 °C during 24 h. Bacteria cells and isolated colonies were described. API 50CH/B was performed and MALDI-TOF MS was used for external quality control. Thirty- five (66%) isolates representing 4 genera (Bacillus, Paenibacillus, Brevisbacillus and Lysinibacillus) including 10 species were identified. The most important species were Bacillus cereus (30%) and Bacillus licheniformis (21%). Eighteen (34%) isolates were non-reactive Bacillus. The overall contamination rate on LJ with VCNT at 10 µg of vancomycin was statistically lower than which without VCNT (18.7% versus 43.8%) (p = 0.01). The most important SFB identified were B. cereus and B. licheniformis. Almost all identified strains were similar to those currently isolated in fermented traditional food suggesting in part food related contaminants. VCNT containing 10 µg of vancomycin is a good alternative method to reduce mycobacterial culture contamination.

The Biotechnology of Ugba, a Nigerian Traditional Fermented Food Condiment

Legumes and oil bean seeds used for the production of condiments in Africa are inedible in their natural state; they contain some anti-nutritional factors especially undigestible oligosaccharides and phytate. Fermentation impact desirable changes by reducing anti-nutritional factors and increasing digestibility. Ugba is an alkaline fermented African oil bean cotyledon (Pentaclethra macrophylla) produced by the Ibos and other ethnic groups in southern Nigeria. Seen as a family business in many homes, its preparation is in accordance with handed-down tradition from previous generations and serves as a cheap source of plant protein. Its consumption as a native salad is made possible by fermentation of the cotyledon for 2–5 days, but could also serve as a soup flavoring agent when fermentation last for 6–10 days. The fermentation process involved is usually natural with an attendant issue of product safety, quality and inconsistency. The production of this condiment is on a small scale and the equipment used are very rudimentary, devoid of good manufacturing procedures that call to question the issue of microbial safety. This paper therefore reviews the production process and the spectrum of microbial composition involved during fermentation. In addition, potential spoilage agents, nutritional and biochemical changes during production are examined. Furthermore, information that can support development of starter cultures for controlled fermentation process in order to guarantee microbiological safety, quality and improved shelf life are also discussed.

Produce from Africa's Gardens: Potential for Leafy Vegetable and Fruit Fermentations

A rich variety of indigenous fruits and vegetables grow in Africa, which contribute to the nutrition and health of Africa's populations. Fruits and vegetables have high moisture and are thus inherently prone to accelerated spoilage. Food fermentation still plays a major role in combating food spoilage and foodborne diseases that are prevalent in many of Africa's resource disadvantaged regions. Lactic acid fermentation is probably the oldest and best-accepted food processing method among the African people, and is largely a home-based process. Fermentation of leafy vegetables and fruits is, however, underutilized in Africa, although such fermented products could contribute toward improving nutrition and food security in this continent, where many are still malnourished and suffer from hidden hunger. Fermentation of leafy vegetables and fruits may not only improve safety and prolong shelf life, but may also enhance the availability of some trace minerals, vitamins and anti-oxidants. Cassava, cow-peas, amaranth, African nightshade, and spider plant leaves have a potential for fermentation, as do various fruits for the production of vinegars or fruit beers and wines. What is needed to accelerate efforts for production of fermented leaves and vegetables is the development of fermentation protocols, training of personnel and scale-up of production methods. Furthermore, suitable starter cultures need to be developed and produced to guarantee the success of the fermentations.

Review: Diversity of Microorganisms in Global Fermented Foods and Beverages

Culturalable and non-culturable microorganisms naturally ferment majority of global fermented foods and beverages. Traditional food fermentation represents an extremely valuable cultural heritage in most regions, and harbors a huge genetic potential of valuable but hitherto undiscovered strains. Holistic approaches for identification and complete profiling of both culturalable and non-culturable microorganisms in global fermented foods are of interest to food microbiologists. The application of culture-independent technique has thrown new light on the diversity of a number of hitherto unknown and non-cultural microorganisms in naturally fermented foods. Functional bacterial groups ("phylotypes") may be reflected by their mRNA expression in a particular substrate and not by mere DNA-level detection. An attempt has been made to review the microbiology of some fermented foods and alcoholic beverages of the world.

Combination of culture-independent and culture-dependent molecular methods for the determination of bacterial community of iru, a fermented Parkia biglobosa seeds

In this study, bacterial composition of iru produced by natural, uncontrolled fermentation of Parkia biglobosa seeds was assessed using culture-independent method in combination with culture-based genotypic typing techniques. PCR-denaturing gradient gel electrophoresis (DGGE) revealed similarity in DNA fragments with the two DNA extraction methods used and confirmed bacterial diversity in the 16 iru samples from different production regions. DNA sequencing of the highly variable V3 region of the 16S rRNA genes obtained from PCR-DGGE identified species related to Bacillus subtilis as consistent bacterial species in the fermented samples, while other major bands were identified as close relatives of Staphylococcus vitulinus, Morganella morganii, B. thuringiensis, S. saprophyticus, Tetragenococcus halophilus, Ureibacillus thermosphaericus, Brevibacillus parabrevis, Salinicoccus jeotgali, Brevibacterium sp. and uncultured bacteria clones. Bacillus species were cultured as potential starter cultures and clonal relationship of different isolates determined using amplified ribosomal DNA restriction analysis (ARDRA) combined with 16S-23S rRNA gene internal transcribed spacer (ITS) PCR amplification, restriction analysis (ITS-PCR-RFLP), and randomly amplified polymorphic DNA (RAPD-PCR). This further discriminated B. subtilis and its variants from food-borne pathogens such as B. cereus and suggested the need for development of controlled fermentation processes and good manufacturing practices (GMP) for iru production to achieve product consistency, safety quality, and improved shelf life.