Isolation and identification of phytase-active yeasts from sourdoughs

Nuobariene, Lina; Hansen, Åse; Arneborg, Nils

doi:10.1016/j.lwt.2012.03.011

Cited by 33 publications

(38 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Five species belonged to the Saccharomycotina subphylum and among them most were in the Kazachstania clade: K. unispora, K. exigua, K. bulderi and C. humilis (Kurtzman and Robnett, 2003). All the dominant yeast species, except K. bulderi, have already been described in bakery products (Minervini et al, 2012a;Nuobariene et al, 2012;Palomba et al, 2010;Valmorri et al, 2010;Vrancken et al, 2010;Zhang et al, 2011). Among 69 natural sourdoughs previously analyzed in Italy, Belgium, Denmark and China, more than 90% contained S. cerevisiae, 23% C. humilis and 3% K. unispora (Gullo et al, 2003;Minervini et al, 2012a;Nuobariene et al, 2012;Palomba et al, 2010;Scheirlinck et al, 2007;Valmorri et al, 2010;Vrancken et al, 2010;Zhang et al, 2011).…”

Section: Discussionmentioning

confidence: 96%

Sourdough microbial community dynamics: An analysis during French organic bread-making processes

Lhomme

Urien

Legrand³

et al. 2016

Food Microbiology

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 96%

Sourdough microbial community dynamics: An analysis during French organic bread-making processes

Lhomme

Urien

Legrand³

et al. 2016

Food Microbiology

View full text Add to dashboard Cite

“…As mentioned, there are some possible pitfalls when using released P i as measure of phytase activity; presence of non-phytase phosphatases, presence of additional sources of phosphate in the extract and/or assay substrate, and the fact that the products of IP 6 degradation are also substrates for the enzyme. In Figure 2 it is seen that both IP 4 and IP 3 are formed during the first 15 min of assay, which is a result from the degradation of (and simultaneous P i release from) IP 5 and IP 4 respectively.…”

Section: Discussionmentioning

confidence: 99%

“…Degradation of lower inositol phosphates may be practically important from a nutritional point of view since IP 5 , IP 4 and IP 3 also interfere with mineral absorption from the diet [29,30] and also for the feed industry, where release of phosphate is the main issue. To allow reliable comparisons of the enzymatic activities between different samples and from different studies, it is important to specify what type of enzymatic activity that is determined.…”

Section: Discussionmentioning

confidence: 99%

“…Phytase activity determinations are often based on analyzing released phosphate by colorimetric analysis methods [2][3][4][5][6]. This is many times sufficient since the released amount of P i per time is often the relevant parameter, for example in feed applications.…”

Section: Introductionmentioning

confidence: 99%

“…Assessing phytase activity can be tricky in several ways: First, one of the products of the phytase reaction (IP 5 ) is also substrate for the same enzyme and so is the subsequent products (IP 4 and down). This means that if we define phytase activity as degradation of phytate (IP 6 only), there will be competing substrates present in such assays.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Assessing phytase activity

2015

View full text Add to dashboard Cite

Phytases are nutritionally important for increased bioavailability of dietary minerals and phosphate for monogastric animals including humans. Release of minerals and phosphate is accomplished by the enzymatic stepwise degradation of phytate (inositol hexaphosphate, IP 6 ). Activity determinations of phytase is often based on analysis of total released phosphate (P i ), but phytase activity in its purest form represents released product per time from IP 6 only. Microbial and plant preparations often also contain mixtures of phosphatases and organic phosphate compounds; hence some released phosphate in enzymatic assays may originate from non-phytase phosphatases degrading non-phytate molecules. Moreover, even purified enzyme extracts assessed via P i release may result in errors, since commercial IP 6 commonly contains contamination of lower inositol phosphates, and further, the products of phytase IP 6 hydrolysis are also substrates for the phytase. These facts motivate a quantitative comparative study. We compared enzyme activity determination in phytase assay samples at four different time points, based on analyzing the substrate IP 6 versus the product P i using different selected methods. The calculated activities varied substantially. For example, at 15 min into enzymatic assay, variations from 152 mU/ml (by IP 6 analysis on HPIC) to 275-586 mU/ml (by P i analysis using several methods) was detected. Our work emphasizes the importance of defining the type of activity assessed, showing that phytase activity based on released P i may yield false positive results and/or overestimations. We propose to differentiate between phytase activity, being the activity by which IP 6 is degraded, and total inositol phosphatase activity, corresponding to total released phosphate during the enzymatic reaction.

show abstract

Isolation and identification of lactic acid bacteria with phytase activity from sourdough

Mohammadi‐Kouchesfahani

Hamidi‐Esfahani

Azizi

2019

Food Science & Nutrition

View full text Add to dashboard Cite

Wholemeal bread is strongly recommended due to its nutritional value. However, whole‐grain foods contain a high level of phytic acid, an antinutritional factor that decreases the mineral bioavailability. The objective of this study was isolation and identification of lactic acid bacteria with phytase activity to find a suitable starter for bread‐making. Wheat–legume sourdoughs were prepared by the back‐slopping procedure. Lactic acid bacteria were isolated from the sourdough of wheat flour–mung bean, and their phytase activity was tested in the solid and liquid media. Out of the nine phytase‐active isolates in the solid medium, only three isolates produced extracellular phytase in the liquid medium with activity ranging from 16.3 to 53.2 (U/ml). These isolates belonged to species Weissella confusa mk.zh95 and Pediococcus pentosaceus. The highest phytase activity was found for Weissella confusa mk.zh95. Weissella confusa mk.zh95 is considered an interesting source of phytase during cereals and legumes fermentation which improves the bioavailability of minerals.

show abstract

Isolation and identification of phytase-active yeasts from sourdoughs

Cited by 33 publications

References 39 publications

Sourdough microbial community dynamics: An analysis during French organic bread-making processes

Sourdough microbial community dynamics: An analysis during French organic bread-making processes

Assessing phytase activity

Isolation and identification of lactic acid bacteria with phytase activity from sourdough

Contact Info

Product

Resources

About