Hydrolysis of phytic acid by intrinsic plant or supplemented microbial phytase (Aspergillus niger) in the stomach and small intestine of minipigs fitted with re-entrant cannulas. 1. Passage of dry matter and total phosphorus

Abstract. Phosphorus (P) is an essential nutrient for living organisms. Under P-limiting conditions plants and microorganisms can exude extracellular phosphatases that release inorganic phosphate (Pi) from organic phosphorus compounds (Porg). Phytic acid (myo-inositol hexakisphosphate, IP6) is an important form of Porg in many soils. The enzymatic hydrolysis of IP6 by phytase yields available Pi and less phosphorylated inositol derivates as products. The hydrolysis of organic P compounds by phosphatases leaves an isotopic imprint on the oxygen isotope composition (δ18O) of released Pi, which might be used to trace P in the environment. This study aims at determining the effect of phytase on the oxygen isotope composition of released Pi. For this purpose, enzymatic assays with histidine acid phytases from wheat and Aspergillus niger were prepared using IP6, adenosine 5'-monophosphate (AMP) and glycerophosphate (GPO4) as substrates. For a comparison to the δ18O of Pi released by other extracellular enzymes, enzymatic assays with acid phosphatases from potato and wheat germ with IP6 as a substrate were prepared. During the hydrolysis of IP6 by phytase, four of the six Pi were released, and one oxygen atom from water was incorporated into each Pi. This incorporation of oxygen from water into Pi was subject to an apparent inverse isotopic fractionation (&varepsilon; ~ 6 to 10 ‰), which was similar to that imparted by acid phosphatase from potato during the hydrolysis of IP6 (&varepsilon; ~ 7 ‰), where less than three Pi were released. The incorporation of oxygen from water into Pi during the hydrolysis of AMP and GPO4 by phytase yielded a normal isotopic fractionation (&varepsilon; ~ −12 ‰), similar to values reported for acid phosphatases from potato and wheat germ. We attribute this similarity in &varepsilon; to the same amino acid sequence motif (RHGXRXP) at the active site of these enzymes, which leads to similar reaction mechanisms. We suggest that the striking substrate dependency of the isotopic fractionation could be attributed to a difference in the δ18O values of the C–O–P bridging and non-bridging oxygen atoms in organic phosphate compounds.

Download Full-text

Improvement of Enzymatic Saccharification of Cellulose-Containing Raw Materials Using Aspergillus niger

Processes ◽

10.3390/pr9081360 ◽

2021 ◽

Vol 9 (8) ◽

pp. 1360

Author(s):

Ekaterina Budenkova ◽

Stanislav Sukhikh ◽

Svetlana Ivanova ◽

Olga Babich ◽

Vyacheslav Dolganyuk ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Aspergillus Niger ◽

Filter Paper ◽

Raw Materials ◽

Enzymatic Saccharification ◽

Wood Chip ◽

Cellulase Activity ◽

Wood Chips ◽

Acid Pretreatment ◽

Hydrolysis Of

Enzymatic hydrolysis of cellulose-containing raw materials, using Aspergillus niger, were studied. Filter paper, secondary cellulose-containing or starch-containing raw materials, miscanthus cellulose after alkaline or acid pretreatment, and wood chip cellulose, were used as substrates. The study focused on a wild A. niger strain, treated, or not (control), by ultraviolet (UV) irradiations for 45, 60, or 120 min (UV45, UV60, or UV120), or by UV irradiation for 120 min followed by a chemical treatment with NaN3 + ItBr for 30 min or 80 min (UV120 + CH30 or UV120 + CH80). A mixture of all the A. niger strains (MIX) was also tested. A citrate buffer, at 50 mM, wasthe most suitable for enzymatic hydrolysis. As the UV exposure time increased to 2 h, the cellulase activity of the surviving culturewas increased (r = 0.706; p < 0.05). The enzymatic activities of the obtained strains, towards miscanthus cellulose, wood chips, and filter paper, were inferior to those obtained with commercial enzymes (8.6 versus 9.1 IU), in some cases. Under stationary hydrolysis at 37 °C, pH = 4.7, the enzymatic activity of A. niger UV120 + CH30 was 24.9 IU. The enzymatic hydrolysis of secondary raw materials, using treated A. niger strains, was themost effective at 37 °C. Similarly, the most effective treatment of miscanthus cellulose and wood chips occurred at 50 °C. The maximum conversion of cellulose to glucose was observed using miscanthus cellulose (with alkaline pretreatment), and the minimum conversion was observed when using wood chips. The greatest value of cellulase activity was evidenced in the starch-containing raw materials, indicating that A. niger can ferment not only through cellulase activity, but also via an amylolytic one.

Download Full-text

DIGESTION OF NUTRIENTS IN THE SMALL INTESTINE OF PIGS FED DIETS CONTAINING RAW AND AUTOCLAVED FABA BEANS

Canadian Journal of Animal Science ◽

10.4141/cjas76-056 ◽

1976 ◽

Vol 56 (3) ◽

pp. 451-456 ◽

Cited By ~ 14

Author(s):

M. IVAN ◽

J. P. BOWLAND

Keyword(s):

Amino Acids ◽

Small Intestine ◽

Beneficial Effect ◽

Dietary Protein ◽

Dry Matter ◽

Latin Square ◽

Sole Source ◽

Intestinal Uptake ◽

Gross Energy ◽

Faba Beans

Four castrated pigs, each fitted with a re-entrant cannula in the terminal ileum, were used to study digestion in the small intestine. A nitrogen-free diet was used for the estimation of metabolic nitrogen and amino acids. Faba beans, as the sole source of dietary protein, were used raw or after autoclaving for 30 or 60 min. The four diets were fed to the pigs in a 4 × 4 latin square experiment. The pigs were fed each diet for 6 days prior to a 24-hr collection of total ileal contents. Autoclaving of faba beans had no significant effect on digestibility of dry matter, gross energy, nitrogen and individual amino acids except arginine, which was significantly increased. The intestinal uptake of arginine was the highest and of cystine the lowest in all faba bean diets. It was concluded that autoclaving faba beans had no beneficial effect on the digestion of nutrients in the small intestine of the pig.

Download Full-text

PHOSPHORUS NUTRITION OF SOYBEANS AS AFFECTED BY PLACEMENT OF FERTILIZER PHOSPHORUS

Canadian Journal of Soil Science ◽

10.4141/cjss83-021 ◽

1983 ◽

Vol 63 (2) ◽

pp. 199-210 ◽

Cited By ~ 4

Author(s):

C. W. BULLEN ◽

R. J. SOPER ◽

L. D. BAILEY

Keyword(s):

Glycine Max ◽

Total Phosphorus ◽

Dry Matter ◽

Field Experiments ◽

Seedling Emergence ◽

Phosphorus Uptake ◽

Growth Chamber ◽

Grain Yields ◽

Chamber Experiment ◽

Glycine Max L

Growth chamber and field experiments were conducted on Southern Manitoba soils, low in available soil phosphorus, to investigate the effects of various placement methods and levels of phosphorus fertilizer on soybean (Glycine max (L.) Merrill ’Maple Presto’). It was found that soybean responded well to applied phosphorus on low-P soil in growth chamber studies. In the first growth chamber experiment, P was applied in solution to 100%, 50%, 25%, 12.5% and 1% of the total soil volume. Dry matter yields, total phosphorus uptake and utilization of fertilizer P increased at each level of applied P as the size of the phosphated band was decreased. The results were partly attributed to greater chemical availability of P in the smaller zones of P fertilizer reaction. In a second growth chamber experiment, soybeans responded differently to phosphorus banded in six different locations. Placement of the fertilizer 2.5 cm directly below the seed was more effective in increasing dry matter yield, total phosphorus uptake and fertilizer P utilization than placement 2.5 cm and 5 cm away at the same depth or placement 5 cm below the seed, whether the band was directly below, 2.5 cm away or 5 cm away. Soybean yield responses in the field were greatest with P banded 2.5 cm directly below the seed on low-P soils. Placement of P 2.5 cm below the seed resulted in grain yields that were 64% and 50% higher (at the two sites) than those obtained in control plots. Sidebanding P, 2.5 cm below and 2.5 cm away from the seed at the same level of application, improved grain yields of control plots by 40% and 39%. Seed placement and broadcast applications of P were not as effective in increasing grain yields. Broadcasting P in fall or in spring at rates of up to 52.38 kg P/ha did not result in significantly higher grain yields than those obtained in control plots. Placement of P in contact with the seed appeared to reduce seedling emergence, resulting in depressed yields when 52.38 kg P/ha were applied. Key words: Glycine max L. Merrill, ’Maple Presto’

Download Full-text

Effect of supplementary Aspergillus niger phytase in diets for piglets on their performance and apparent digestibility of phosphorus

Animal Science ◽

10.1017/s0003356100021127 ◽

1992 ◽

Vol 55 (3) ◽

pp. 425-430 ◽

Cited By ~ 32

Author(s):

S. Beers ◽

A. W. Jongbloed

Keyword(s):

Aspergillus Niger ◽

Average Daily Gain ◽

Live Weight ◽

Basal Diet ◽

Apparent Digestibility ◽

Feeding Trial ◽

Daily Food ◽

Microbial Phytase ◽

Daily Gain ◽

Aspergillus Niger Phytase

AbstractA total of 384 piglets from a three-way cross Yorkshire ♂ × (Finnish Landrace ♂ × Dutch Landrace♀) ♀ in the live-weight range of 11 to 25 kg were used in a feeding trial. The effect of supplementary microbial phytase from Aspergillus niger var. Van Tieghem on performance (average daily gain (ADG), average daily food intake (ADFI) and food conversion ratio (FCR)) and apparent digestibility of total phosphorus (P), in comparison with a non-supplemented basal diet or a diet supplemented with one or two levels of monocalcium phosphate (MCP), were studied.The piglets were allotted to 12 blocks. Within each block, four experimental diets were offered ad libitum for a period of 4 weeks i.e. (1) basal diet; (2) basal diet + 1·0 g P, from MCP per kg diet; (3) basal diet + 1·9 g P, from MCP per kg diet; and (4) basal diet + 1450 phytase units (PTU) per kg diet. The diets, with added chromium III oxide as a marker, were cold pelleted without steam at a temperature not above 60°C to avoid a possible inactivation of the phytase. In all diets the ratio calcium: digestible P was intended to be constant.Adding 1450 PTU of Aspergillus niger phytase enhanced the apparent digestibility of P by proportionately 0·216 when compared with diet 1 and by proportionately 0·100 compared with diet 3. In addition, significantly higher ADG and ADFI and better FCR were noted in pigs receiving supplementary microbial phytase than in pigs on any other treatment. The content of digestible P of the diet with added phytase, however, zvas between the two levels of the diets with added MCP.

Download Full-text