ISSN: 2345-5357

Vol. 4 No. 2 (2017)

Original Article


Study on the Effect of Levulinic Acid on Whey-Based Biosynthesis of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by Hydrogenophaga pseudoflava

Martin Koller, Paula Hesse, Hubert Fasl, Franz Stelzer, Gerhart Braunegg

Applied Food Biotechnology, Vol. 4 No. 2 (2017), 5 April 2017 , Page pp. 65-78
https://doi.org/10.22037/afb.v4i2.16337

Background and Objective: Production of polyhydroxyalkanoate copolyesters consisting of 3-hydroxybutyrate and 3-hydroxyvalerate units was for the first time studied using the production strain Hydrogenophaga pseudoflava based on sustainable raw materials. This strategy provides for increased cost efficiency in PHA production and in enhanced material quality.

Material and Methods: As a particularity, production of these poly(3-hydroxybutyrate-co-3- hydroxyvalerate) copolyesters was based on a novel substrate/co-substrate combination: whey permeate from dairy industry, on the one hand, acted as substrate for biomass and 3HB biosynthesis; on the other hand, levulinic acid, accessible from various renewable resources, was used as 3HV-related precursor compound. The experiments were carried out on shaking flask scale using defined nutrient media.

Results and Conclusion: Applied during nutritionally balanced growth of H. pseudoflava, levulinicacid displays drastic growth inhibition at rather low concentrations of 0.2 g l-1 (growth inhibition constant Ki = 0.032), which suggests the careful supply of this compound in the first phase of cultivation. Under nitrogen-free cultivation conditions, inhibition of the strain´s metabolism by levulinic acid was less pronounced. Here, poly(3-hydroxybutyrate-co- 3-hydroxyvalerate) concentrations up to 4.2 g l-1 and volumetric poly(3-hydroxybutyrate-co-3- hydroxyvalerate) productivities up to 0.06 g l-1 h -1 were achieved in dependence on the precursor supply. Investigating poly(3-hydroxybutyrate-co-3-hydroxyvalerate) composition in setups supplied with differently composed whey/levulinic acid mixtures revealed 3- hydroxyvalerate fractions in the polymer between 0 and 0.6 mol mol-1 . This study successfully demonstrates the feasibility of combined utilization of different waste- and by-products from food industry and agriculture for generation of value-added 2nd generation biopolymers.

Conflict of interest: The authors declare no conflict of interest.

Background and Objective: Time-temperature indicators are used in smart packaging, and described as intelligent tools attached to the label of food products to monitor their timetemperature history. Since the previous studies on microbial time-temperature indicators were only based on pH-dependent changes, and they were long-time response indicators, in the present work, a new microbial time-temperature indicator was designed by using the alpha amylase activity of Bacillus amyloliquefaciens vegetative cells.
Material and Methods: The designed time-temperature indicator system consists of Bacillus amyloliquefaciens, specific substrate medium and iodine reagent. The relation of the timetemperature
indicator’ response to the growth and metabolic activity (starch consumption and production of reduced sugars) of Bacillus amyloliquefaciens was studied. In addition, the temperature dependence of the time-temperature indicator was considered at 8 and 28˚C. Finally, in order to adjust time-temperature indicator endpoint, the effect of the inoculum level was investigated at 8ºC.
Results and Conclusion: In the designed system, a color change of an iodine reagent to yellow progressively occurs due to the starch hydrolysis. The effect of the inoculum level showed the negative linear relationship between the levels of Bacillus amyloliquefaciens inoculated in the medium and the endpoints of the time-temperature indicators. The endpoints were adjusted to 156, 72 and 36 hours at the inoculum levels of 102, 104 and 106 CFU ml-1, respectively. The main advantages of the time-temperature indicator is low cost and application for monitoring the quality of chilled food products.
Conflict of interest: The authors declare no conflict of interest.

Enhanced Sorbitol Production under Submerged Fermentation using Lactobacillus plantarum

Khan Nadiya Jan, Abhishek Dutt Tripathi, Shubhendra Singh, Diksha Surya, Surendra Prasad Singh

Applied Food Biotechnology, Vol. 4 No. 2 (2017), 5 April 2017 , Page pp. 85-92
https://doi.org/10.22037/afb.v4i2.13514

Background and Objective: Sorbitol is a non-toxic and slightly hygroscopic compound with different applications. Zymomonas mobiles produces sorbitol from sucrose or mixtures of glucose and fructose (formation is coupled with the dehydrogenation of glucose to glucono-δ- lactone). Recombinant Zymomonas mobilis may produce sorbitol and gluconic acid from glucose and fructose using different divalent metal ions with reduced the ethanol yield and
significantly increased yield of sorbitol. Current study envisaged to alter the media components, physical process parameters and supplementation of amino acids for enhanced sorbitol production.
Material and Methods: Several process variables were evaluated on sorbitol production including carbon sources (glucose, fructose, maltose, sucrose), carbon concentrations (5, 10, 20 and 25 g l-1), nitrogen sources (peptone, tryptone, yeast extract, beef extract and organic nitrogen mix), temperatures (25, 29, 33, 37, 41°C), pH (6, 6.5, 7 , 7.5 ,8), agitation rate (50, 100, 150, 200 rpm) and amino acids (cysteine, cystine, tryptophan)in batch cultivation of
Lactobacillus plantarum NCIM 2912. Shake flask cultivation performed under optimum conditions like temperature 37°C, pH 7.0 and agitation rate of 150 rpm, resulted in enhanced sorbitol production. Comparative study of sorbitol production in solid state fermentation and submerged fermentation was also evaluated.
Results and Conclusion: Batch cultivation under submerged conditions further performed in 7.5-l lab scale bioreactor (working volume 3.0-l) under optimized conditions resulted in maximum cell biomass of 8.95±0.03 g g-1 and a sorbitol content of 9.78±0.04 g l-1 after 42.0 h of fermentation. Scale up study on bioreactor resulted in maximum sorbitol yield (Yp/x) and productivity of 1.11 g g-1 and 0.50 g l-1 h under submerged fermentation, respectively.
Conflict of interest: The authors declare no conflict of interest.

Physicochemical Properties and Sensory Evaluation of Reduced Fat Fermented Functional Beef Sausage

Faleeha Hasan Hussein, Seyed Hadi Razavi, zahra Emam Djomeh

Applied Food Biotechnology, Vol. 4 No. 2 (2017), 5 April 2017 , Page pp. 93-102
https://doi.org/10.22037/afb.v4i2.15181

Background and Objective: Semi-dry fermented sausages were manufactured from beef meat in three types: without starter culture (control), inoculated with Lactobacillus casei and inoculated with Lactobacillus paracasei. Probiotic fermented sausages are safe and healthy meat products, which receive high commercial interest and growing market shares.
Material and Methods: The physico–chemical characteristics (Protein, Moisture, Fat, Ash, Lactic acid value and pH), microbiological features (total aerobic, total mold and yeast and
lactic acid bacteria count) and sensory evaluation (color, flavor, texture and overall acceptability) were analyzed after 0, 10, 20, 30, 40 and 45 days of refrigerated storage at 4°C.
Results and Conclusion: There was a significant difference (p≤0.05) in moisture content, which decreased in all samples during the period of refrigerated storage. However, all other parameters such as protein, fat and ash increased. The lactic acid produced during the fermentation by lactic acid bacteria resulted in a decrease in the pH value of all samples, and improved sensory evaluation of the fermented sausage inoculated with Lactobacillus casei and Lactobacillus paracasei during the storage period. The best results were obtained in the fermented sausage inoculated with Lactobacillus paracasei in physico-chemical, microbial and sensory characteristics. Also we could preserve the product at 4°C for 45 days.
Conflict of interest: The authors declare that there is no conflict of interest.

Production of Amylase by Bacillus polymyxa NCIM No. 2539 from Agroindustrial Wastes

Abhishek Dutt Tripathi, Ankita Joshi, Surendra Prasad Singh, Arpit Shrivastava

Applied Food Biotechnology, Vol. 4 No. 2 (2017), 5 April 2017 , Page pp. 103-112
https://doi.org/10.22037/afb.v4i2.15471

Background and Objective: In the present study, Bacillus polymyxa NCIM No. 2539 was selected to utilize agro-industrial byproduct (orange peel) for amylase production under submerged
fermentation conditions.
Material and Methods: Different agro-industrial byproducts like cane molasses, wheat bran, rice bran and orange peel were screened for maximum amylase production. Amylase activitiy of Bacillus polymyxa was studied using starch-agar plate method. MINITAB software Version 17 and central composite design were applied to evaluate effect of supplementation of substrate with different sulphur containing amino acids (cysteine, methionine and cystine) and vitamin thiamine on enzyme activity. Further optimization of the parameters viz. amount of substrate, concentration of amino acid and vitamin for maximum amylase production was studied by central composite rotatable design.
Results and Conclusion: Among 4 different agro-industrial substrates applied, orange peel showed maximum enzyme production (activity: 492.31 IU g-1 sample). Supplementation of the production media with cysteine showed maximum amylase
production (515.38 IU g-1 sample) among all three amino acids and control. Supplementation with thiamine also showed more amylase production (469.23 IU g-1 sample) as compared to control (415.38 IU g-1). Cysteine and thiamine proved to increase
amylase production significantly. Maximum amylase production was obtained at 7.7 g orange peel, 37.29 mg cysteine and 34.23 mg per 10 ml thiamine.
Conflict of interest: The authors declare no conflict of interest.

Enzymatic Synthesis of Theanine in the Presence of L-glutaminase Produced by Trichoderma koningii

Iran Alemzadeh, Minoo Sakhaei

Applied Food Biotechnology, Vol. 4 No. 2 (2017), 5 April 2017 , Page pp. 113-121
https://doi.org/10.22037/afb.v4i2.15713

Background and Objective: Since ancient times, it has been said that drinking green tea brings relaxation. The substance that is responsible for a sense of relaxation is theanine. Theanine (γ-glutamylethylamide) is a unique non-protein amino acid. It gives an umami taste and a unique flavor to the tea, and has many physiological and pharmaceutical effects such as anti-tumor, anti-cancer, neuro-protective, anti-hypertensive and anti-obesity effects; it may further help in relaxation and increase focus. So this compound is essential for human body; however, it is not synthesized in the body and should be administrated orally. In the present study, the enzymatic biosynthesis of theanine was examined in the presence of Ethylamine and L-glutamine, and for the first time the enzyme was produced by the fungal strain Trichoderma koningii.
Material and Methods: At first, solid state fermentation was carried out for the production of L-glutaminase by the fungal strain Trichoderma koningii using sesamum oil cake as the solid substrate. Then the biosynthesis of theanine was performed in the presence of extracted enzyme solution, and ethylamine and L-glutamine as substrates. The concentration of effective parameters, namely L-glutamine and ethylamine, and the volume of enzyme solution on theanine production were evaluated based on the response surface methodology coupled with central composite design. 16 experiments were designed by the design expert software and carried out to examine the changes of theanine concentration with changes in the concentration of ethylamine and L-glutamine and the volume of enzyme solution.
Results and Conclusion: This investigation indicated simultaneous synthesis of theanine as well as hydrolysis of L-glutamine and L-glutamic acid. Selected independent variables (including ethylamine concentration, L-glutamine concentration and enzyme solution volume) were effective on theanine concentration. Increase of enzyme solution volume had a significant effect on theanine concentration. The highest theanine concentration (43 mM) was obtained at the ethylamine concentration of 0.9 M, L-glutamine concentration of 0.3 M and enzyme solution of 3 ml.
Conflict of interest: The authors declare no conflict of interest.