In vitro screening of EPS-producing Streptococcus thermophilus strains for their probiotic potential from Dahi.

Dahi is a very common and traditional fermented dairy product in Pakistan and its neighboring countries, it represents a rich source for the isolation of many new strains of lactic acid bacteria (LAB). The major objective of this study was to evaluate the probiotic potential of novel exopolysaccharide (EPS)-producing strains of S. thermophilus isolated from Dahi, sold in the local markets of Rawalpindi and Islamabad, Pakistan. In this study, 32 isolates of S. thermophilus were initially isolated from Dahi and out of these, 10 identified strains were further screened for their EPS-producing ability. Maximum EPS production was estimated for RIY strain (133.0 ± 0.06), followed by RIH4 strain (103.83 ± 0.76) and RIRT2 strain (95.77 ± 0.22), respectively. Thereafter, in vitro studies revealed that these newly identified EPS-producing strains of S. thermophilus fulfilled the basic requirements for probiotic functions; including resistance to harsh conditions of GIT, good cell surface hydrophobicity, auto-aggregation, and co-aggregation, especially against L. monocytogenes. Finally, the safety assessment displayed that these strains were also sensitive to clinical antibiotics, including vancomycin. Thus, these selected EPS strains of S. thermophilus act as potential candidates for biostabilizers in the preparation of consumer-friendly fermented probiotic milk products.

Gastrointestinal transit tolerance, cell surface hydrophobicity, and functional attributes of Lactobacillus Acidophilus strains isolated from Indigenous Dahi.

Strains of Lactobacillus acidophilus WFA1 (KU877440), WFA2 (KU877441), and WFA3 (KU877442) were isolated from indigenous Dahi (yogurt), screened, and selected based on acid and bile tolerance along with the antimicrobial activity. These selected strains were further assessed for their probiotic and functional attributes. Results for simulated gastric and intestinal tolerance/ resistance revealed that all three strains can resist and survive under the following mentioned conditions. To access cell surface hydrophobicity, bacterial adhesion to hydrocarbons (BATH), cellular auto-aggregation, and salt aggregation were performed. In BATH, adhesion of strains against three hydrocarbons namely xylene, dichloromethane, and hexadecane was conducted. The results show that strains showed the least adhesion to xylene (54.25%) as compared to dichloromethane (55.25%) and hexadecane (56.65%). WFA1 showed maximum adherence percentage (55.48%) followed WFA2 (55.48%) and WFA3 (51.38%). Cellular auto-aggregation varied from 21.72% to 30.73% for WFA3 and WFA1, respectively. In the salt aggregation test (SAT), WFA1, WFA2, and WFA3 aggregated at 0.6, 1.0, and 2.0 molar concentrations of ammonium sulfate, respectively. PCR amplification of bile salt hydrolase gene (bsh) was performed and sequences were submitted to the public database of NCBI and Gene bank under accession numbers, KY689139, KY689140, and KY689141. Additionally, a cholesterol-lowering assay was conducted and up to 26% reduction in cholesterol was observed by the strains. Regarding functional properties, exopolysaccharide (EPS) production, and antioxidant potential, strain WFA1 showed promising results EPS (1.027mg/ml), DPPH (80.66%), ABTS (81.97%), and reducing power (1.787). It can be concluded from the present study that the mentioned strains of L. acidophilus (WFA1, WFA2, and WFA3) are strongly hydrophobic; thus having an ability to survive and colonize under the gastrointestinal tract which confirms their probiotic nature. Regarding their functional properties, L. acidophilus WFA1 (KU877440) showed excellent properties of antioxidants and EPS production.

Camel milk as an alternative treatment regimen for diabetes therapy.

Camel milk is a valuable source of nutrition with a wide range of therapeutic effects. Its unique composition helps to regulate the blood glucose level. The current study is aimed to evaluate the antidiabetic and hepatoprotective effects, as well as lipid profile restoration of camel milk in the diabetic mouse model. This innovative study evaluates the therapeutic effects of camel milk in diabetic mice by simultaneous measurement of blood glucose, HbA1c, ALT, AST, TG, cholesterol, and histopathological studies. The results showed that camel milk has significantly reduced blood glucose, HbA1c (p < .001), aspartate transaminase (AST), alanine transaminase (ALT) (p < .01), triglyceride (TG), and cholesterol (p < .01), compared to that in the diabetic control group. Also, the therapeutic effects of camel milk were completely comparable with the antidiabetic drug glibenclamide. The results of this study suggest that camel milk could be used as a proper alternative treatment regimen for diabetes therapy.

Isolation and characterization of exopolysaccharide-producing strains of Lactobacillus bulgaricus from curd.

Curd is the most widespread traditional fermented milk product used by a large population and is a good source of vitamin B, protein, and calcium. In this study, the isolation of exopolysaccharide (EPS)-producing strains of Lactobacillus delbrueckii subsp. bulgaricus from curd samples was carried out. Identification of EPS-producing strains was done by Gram staining, catalase activity, sugar fermentation test, API 50 CHL, and PCR analysis. These EPS-producing strains were subjected for the estimation of technological properties such as titratable acidity, curdling time, acidification rate, and texture. The strains best in their technological properties were selected for the production of yogurt in combination with EPS- or non-EPS-producing strains of Streptococcus thermophilus. The EPS concentration range was from 41 to 268 mg/L in the yogurt. The highest value of EPS concentration was detected in S. thermophilus and non-EPS-producing Lb. bulgaricus after 14 days of storage.

Isolation and antimicrobial susceptibility testing of Helicobacter pylori strains from gastric biopsies from Pakistani patients.

Helicobacter pylori is the etiological agent of gastritis and peptic ulcer. This importance had proposed antibiotics as a principle treatment of gastrointestinal pathologies. The focus of this research was to investigate the occurrence of H. pylori in patients having gastritis or gastric ulcer and also draw the susceptibility profile of isolates to several antibiotics. Blood and biopsy specimen from 96 acid peptic disease patients from both sexes were collected. Each sample was used for culture, gram staining, catalase, oxidase, urease and nitrate reduction test by conventional method. Serology using anti Helicobacter pylori IgG was done. The susceptibility profile to six common antibiotics was checked by E- test method. H. pylori was obtained from 40 patients (41.67%) with greater frequency in male (25%) than females (16.67%). With regards to age, H. pylori was recovered highest from the patients between 51-55 (75.86%) years of age. Tetracycline and rifampin were the most effective antibiotics in vitro, while metronidazole was less effective. Nine (22.5%) strains displayed resistance to at least one antimicrobial drug. Whereas, resistance to amoxicillin, ciprofloxacin, clarithromycin, metronidazole and combination of antibiotics like ciprofloxacin, clarithromycin and metronidazole, and ciprofloxin and metronidazole were 11.11, 55.56, 22.22, 33.33, 11.11 and 44.44% respectively. Lower susceptibility profile of H. pylori to antibiotics is because of frequent use of antibiotics to treat other infections.

Optimization and partial characterization of bacteriocin produced by Lactobacillus bulgaricus -TLBFT06 isolated from Dahi.

Lactobacillus bulgaricus is one of the predominant lactic acid bacteria of dahi, conferring technological and functional attributes. In the present study thirty dahi samples were investigated for bacteriocin producing L. bulgaricus. Fourteen different isolates were obtained and five were scrutinized for antibacterial activities against food born pathogens. Amongst, a strain TLB06FT was found to have a wide array of antibacterial activities against Gram positive and negative bacteria was selected for further characterization. Growth media optimization for this strain revealed maximum bacteriocin production on MRS media supplemented with glucose (2%), sodium chloride (1%), Tween-80 (0.5%) and yeast extract (1 %). In addition, optimization of growth conditions revealed maximum bacteriocin production at pH 5.5 and temperature of 30-37°C. Bacteriocin showed thermo stability at 90°C and remained highly active in the pH range of 3.5-7.5, inactive by protein catalyzing enzymes and showed no change in activity (800AumL(-1)) when treated with organic solvents and surfactants. The obtained bacteriocin was purified to 1600AU mL(-1) by ammonium sulfate precipitation (80%) by using dialyzing tubing. In the same way, a single peak was obtained by RP-HPLC having antibacterial activity of 6400AU mL(-1). Thus, wild strains of L. bulgaricus have great potential for the production new and novel type of bacteriocins.

Frequency of parasitic infestation in faecal specimens.

BACKGROUND: Parasitic infestation is very common in developing countries. Major factors of worm infestation are poor socio-economic status, large family size, low educational level, and poor hygiene and sanitation. These parasites lead to nutritional deficiencies and various diseases. A few studies have been carried out in Pakistan and this study tries to find out the frequency of parasitic infestation in our setup. METHODS: A cross sectional study was carried out from December 2011 to February 2012 in Pakistan Aeronautical Complex (PAC) Hospital Kamra. Patients were asked to pass stool specimen in a universal container provided to them from the laboratory. Stool specimens were examined within half an hour by direct light microscopy of faecal smears in normal saline. The laboratory diagnosis was based on the demonstration of ova/cysts or trophozoites. Data were analysed by SPSS-10 and frequency of various parameters was determined. RESULTS: A total of 543 faecal specimens were tested. Specimens found positive for ova/cysts were 295 (54%). Ascaris lumbricoides was the most frequent parasitic infestation in all faecal specimens followed by Taenia saginata. Thirty percent of food handlers were harbouring different parasitic infections. Diarrhoea/dysentery, medical examination of food handlers and for secondment abroad was the most frequent indication for faecal examination. CONCLUSION: High frequency of parasitic infestation in our set up especially of Taenia species requires measures to improve hygiene, water and sanitation. Meat and its products should be obtained from medically fit animals and meat cooked thoroughly before being consumed.

Some probiotic and antibacterial properties of Lactobacillus acidophilus cultured from dahi a native milk product.

In this study, different strains of Lactobacillus acidophilus from dahi were analyzed for certain probiotic and antibacterial properties. Initially, these strains were confirmed by the amplification of 16S rRNA regions and then screened for antibacterial activities against food borne pathogens. The phenotypic relationship between apparent antibacterial activity and cell wall proteins were established by cluster analysis. It was observed that those strains, which have prominent bands having size 22-25 kDa possess antibacterial activity. On the basis of wide spectrum of killing pattern, a strain LA06FT was further characterized that showed no change in its behavior when subjected to the antibiotic protected environment and grow well in acid-bile conditions. The bacteriocin produced by this strain has specific antibacterial activity of 5369.13 AU mg(-1). It remained stable at 60-90 °C and pH range of 4.5-6.5 while proteolytic enzymes inactivate the bacteriocin that confirm its proteinic nature having molecular weight of ≤8.5 kDa.

Lactobacillus acidophilus: characterization of the species and application in food production.

L. acidophilus is a homofermentative, microaerophilic, short chain gram positive microorganism with rod morphology having its bacteriocins belonging to class II a. Several bacteriocins of L. acidophilus have been isolated and characterized. These are structurally similar, but their molecular weight varies as well as their spectrum of antimicrobial activity. They exhibit important technical properties, i.e., thermostability and retaining of activity at a wide pH range along with strong inhibitory actions against food spoilage and pathogenic bacteria make them an important class of biopreservatives. L. acidophilus can be added as an adjunct in many food fermentation processes contributing to unique taste, flavor, and texture. It also preserves the products by producing lactic acid and bacteriocins. A lot of new information regarding the bacteriocins of L. acidophilus has emerged during the last few years. In this review, an attempt has been made to summarize and discuss all the available information regarding the sources of bacteriocins production, their characteristics, and their antimicrobial action along with their application.

Nutritional and health perspectives of beans (Phaseolus vulgaris L.): an overview.

Beans, the variants of Phaseolus vulagris, are nutritionally and economically important food crop in each part of the world. Besides providing nutrients such as multifaceted carbohydrates, elevated proteins, dietary fiber, minerals, and vitamins, these also contain rich variety of polyphenolic compounds with prospective health benefits. This review mainly focuses the important nutritional aspects of beans as well as their contribution in decreasing the risks of chronically degenerative diseases.

Cardio-protective and anti-cancer therapeutic potential of Nigella sativa.

Nigella sativa is the miraculous plant having a lot of nutritional and medicinal benefits, and attracts large number of nutrition and pharmacological researchers. N. sativa seed composition shows that it is the blessing of nature and it contains and many bioactive compounds like thymoquinone, α-hederin, alkaloids, flavonoids, antioxidants, fatty acids many other compounds that have positive effects on curing of different diseases. Several medicinal properties of N. sativa like its anti-cancer, anti-inflammatory, anti-diabetic, antioxidant activities and many others are well acknowledged. However, this article focuses on activity of N. sativa against cardiovascular diseases and cancer. For gathering required data the authors went through vast number of articles using search engines like Science direct, ELSEVIER, Pub Med, Willey on Line Library and Google scholar and the findings were classified on the basis of relevance of the topic and were reviewed in the article. N. sativa is rich source of different biologically active compounds and is found effective in controlling number of cardiovascular diseases and various cancers both in vivo and in vitro studies.

Biophenols and antioxidant properties of Australian canola meal.

During the extraction of canola oil, large quantities of meal are produced. Extracting biophenols from Australian canola meal (ACM) adds value to an otherwise low-value agro-industrial byproduct. This study examined the biophenol content and the antioxidant activity of ACM, the impact of extraction conditions, and varietal differences. Sinapine was the principal biophenol in ACM. In crude and hydrolyzed extracts, 31 compounds were identified: 2 dihexosides, 2 organic acids, 4 glucosinolates, 17 sinapic acid derivatives, 2 cyclic spermidine alkaloids, caffeic acid and its dihexoside, kaempferol, and its C-glucoside. ACM showed significant free radical scavenging activity in DPPH(•) and ABTS(•+) assays. Sinapine was the chief contributor to ACM antioxidant activity, whereas kaempferol sinapoyl triglucoside isomer was the most potent antioxidant. Biophenol content ranged between 12.8 and 15.4 mg GAE/g DW. Differences among studied cultivars were generally quantitative. The Tarcoola cultivar showed the highest biophenol content and antioxidant activity.

Recent trends and applications of encapsulating materials for probiotic stability.

The importance of probiotics and their live delivery in the gastrointestinal tract has gained much importance in the recent past. Many reports have indicated that there is poor viability of probiotic bacteria in dairy based products, both fermented and non-fermented, and also in the human gastro-intestinal system is questionable. In this case, microencapsulation is the most significant emerging and efficient technology that is being used for the preservation of probiotics against adverse environmental conditions. Apart from different techniques of microencapsulation, various types of encapsulating materials are also used for the process, namely, alginate, chitosan, carrageenan, gums (locust bean, gellan gum, xanthan gum, etc.), gelatin, whey protein, starch, and compression coating. Each one of the encapsulating materials has its own unique characteristics of capsule formation and provision of shape, appearance, and strength to microbeads. The type of encapsulating material also influences the viability of probiotics during storage, processing, and in the gastrointestinal tract. The effectiveness of any material depends not upon its capsule forming capability, strength, and enhancing viability but also on its cheapness, availability, and biocompatibility. So, added convenience and reduced packaging costs may also be used to offset the cost of encapsulating one or more ingredients. Encapsulated forms of ingredients provide a longer shelf life for the product.

Selection and characterization of probiotic culture of Streptococcus thermophilus from dahi.

For the isolation of probiotic cultures of Streptococcus thermophilus from dahi, we collected 120 samples from the southern regions of Punjab, Pakistan. Eleven isolates were obtained, and six were scrutinized for antibacterial activities against food-borne pathogens. The carbohydrate fermentation profile of these six strains was determined by the API50 CHL system. Additionally, these strains were amplified for their 16S rRNA regions to confirm their genotypic relationship. Furthermore, phenotypic characteristics among these strains were established by S-layer protein analysis of their cell walls by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and by plasmid profiling. The outer cell wall layers of these strains have 6-14 different sizes of protein bands of 27, 34, 37, 40, 45 and 60 kDa molecular weight. Similarly, except S02FT, all strains have a single prominent plasmid of 23 kbp, whereas S02FT has an additional plasmid of 9 kbp. On the basis of this unique feature and a wide spectrum of killing patterns against pathogenic bacteria, S. thermophilus S02FT was further characterized. This culture showed an optimum antibacterial activity of 800 AU/ml at pH 5.0-5.5 and a temperature of 30-37°C. It grows well in in vitro acidic conditions and tolerates bile salt up to 2% concentration. It was resistant to nalidixic acid, ciprofloxacin, gentamicin and sulphamethoxazol, but showed intermediate behaviour to vancomycin and erythromycin.

Effect of flour processing on the quality characteristics of a soy-based beverage.

Four treatments (roasting, germination, autoclaving and an application of 0.5% EDTA+0.5% sodium hydroxide) were used to reduce the beany flavour of soya beans to produce a soy-based beverage. While germination significantly increased the protein level as compared to the other treatments, the maximum reduction of the beany flavour was achieved by the 0.5% EDTA+0.5% sodium hydroxide application. The soya beans that underwent this treatment were used during the second phase for optimized beverage formulation. During the second phase, a beverage was prepared according to different formulations and analysed for chemical composition and total viable count during a two-month storage period. During storage, the beverage samples exhibited variations in several parameters. The acidity, reducing sugars and total sugars increased, while the ascorbic acid, total soluble solids and pH decreased. Overall, chemical and microbial analyses showed the stability of the product during the storage period.