Optimal Extraction and Deproteinization Method for Mannoprotein Purification from Kluyveromyces marxianus

Background

Mannoproteins, mannose-glycosylated proteins, play an important role in biological processes and have various applications in industries. Several methods have been already used for the extraction of mannoproteins from yeast cell-wall. The aim of this study was to evaluate the extraction and deproteinization of mannan oligosaccharide from the Kluyveromyces (K.) marxianus mannoprotein.

Methods

To acquire crude mannan oligosaccharides, K. marxianus mannoproteins were deproteinized by the Sevage, trichloroacetic acid, and hydrochloric acid (HCL) methods. Total nitrogen, crude protein content, fat, carbohydrate and ash content were measured according to the monograph prepared by the meeting of the Joint FAO/WHO Expert Committee and standard. Mannan oligosaccharide loss, percentage of deproteinization, and chemical composition of the product were assessed to check the proficiency of different methods.

Results

Highly purified (95.4%) mannan oligosaccharide with the highest deproteinization (97.33 ± 0.4%) and mannan oligosaccharide loss (25.1 ± 0.6%) were obtained following HCl method.

Conclusion

HCl, was the most appropriate deproteinization method for the removal of impurities. This preliminary data will support future studies to design scale-up procedures.

Optimal Extraction and Deproteinization Method for Mannoprotein Purification from Kluyveromyces marxianus

Background

Mannoproteins, mannose-glycosylated proteins, play an important role in biological processes and have various applications in industries. Several methods have been already used for the extraction of mannoproteins from yeast cell-wall. The aim of this study was to evaluate the extraction and deproteinization of mannan oligosaccharide from the Kluyveromyces (K.) marxianus mannoprotein.

Methods

To acquire crude mannan oligosaccharides, K. marxianus mannoproteins were deproteinized by the Sevage, trichloroacetic acid, and hydrochloric acid (HCL) methods. Total nitrogen, crude protein content, fat, carbohydrate and ash content were measured according to the monograph prepared by the meeting of the Joint FAO/WHO Expert Committee and standard. Mannan oligosaccharide loss, percentage of deproteinization, and chemical composition of the product were assessed to check the proficiency of different methods.

Results

Highly purified (95.4%) mannan oligosaccharide with the highest deproteinization (97.33 ± 0.4%) and mannan oligosaccharide loss (25.1 ± 0.6%) were obtained following HCl method.

Conclusion

HCl, was the most appropriate deproteinization method for the removal of impurities. This preliminary data will support future studies to design scale-up procedures.

Stress response and characterization of oil-in-water emulsions stabilized with Kluyveromyces marxianus mannoprotein

This study was intended to investigate physico-chemical, rheological, and emulsifying properties of oil-in-water emulsions prepared from the Kluyveromyces marxianus mannoprotein (KMM). Also, the stress-response function of the KMM emulsions was compared with that of the whey protein concentrate (WPC) emulsions in terms of zeta potential, size, and rheology. The stress experiments were conducted at different pH (3 to 9), ionic composition (0 to 500 mM NaCl), and temperatures (30 to 90 °C). The extracted KMM with a molecular weight of 107.2 kDa had 28.8% proteins and 68.22% carbohydrates. With increasing the KMM concentration to 1.5% (w/w), the zeta potential, droplet size, and apparent viscosity of the emulsions reached -35 mV, ∼1 μ, and ∼9 mPa·s, respectively. After applying pH, ionic composition, and temperature, the KMM emulsions were more stable than the WPC emulsions. In conclusion, KMM can be used as a bioemulsifier and be more effective in stabilizing emulsions than WPC. PRACTICAL APPLICATION: Yeasts are a rich source of natural materials. In this study, we extracted mannoproteins from the yeast cell wall and evaluated their functional properties to be used as an emulsifier in oil-in-water emulsions. The results of this study confirm that the yeast-derived mannoproteins are good at stabilizing these emulsions either in the presence or absence of different environmental conditions.

Protected methionine prolonged provision improves summer production and reproduction of lactating dairy cows

The objective was to establish prolonged effects of a rumen-protected Met (RPM) product (SmartamineM) on milk production and reproduction of high-producing early-lactation cows under extended very high ambient temperatures. Twenty four fresh Holstein cows (27 +/- 9 days in milk, 617 kg b.wt., 2.8 body condition score) including 12 second lactation and 12 higher lactation cows were randomly assigned to either control or RPM-supplemented total mixed rations (TMR, 520:480 g kg(-1) forage:concentrate), and were fed continuously for 5 months. Cows were offered TMR 3 times daily post-milking plus a top-dress alfalfa hay. The study was conducted from May through November of 2009 in central Iranian province of Isfahan. The RPM group had consistently greater 5-month-long average DM intake (21.9 vs. 19.1 kg day(-1)), milk yield (42.4 vs. 37.4 kg day(-1)), milk fat content (33 vs. 27.5 g kg(-1)), fat yield (1.40 vs. 1.04 kg day(-1)), milk protein content (29.6 vs. 27.5 g kg(-1)) and protein yield (1.25 vs. 1.02 kg day(-1)). Mature cows tended to produce more milk (42.2 vs. 37.6 kg day(-1)) and milk fat (1.30 vs. 1.13 kg day(-1)) than second lactation cows. The RPM significantly improved ovary function, estrus expression visibility and body condition score (3 vs. 2.6), while shortening days open (106 vs. 143) and calving interval (387 vs. 421 d). Findings provide compelling evidence for beneficial effects of prolonged RPM provision on feed intake, milk production, and reproduction of Holstein cows under concurrent metabolic pressures of early lactation and stressful high ambient temperatures.