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Production of protein by fungi from agricultural wastes
Zbl. Bakt. II. Abt., Bd. 133, S. 619-622 (1978)
[Division of Microbiology, Indian Agricultural Research Institute, New Delhi, India]
Production of Protein by Fungi from Agricultural Wastes VI. Quality of the Protein Formed in Rhizoctonia melongina, Pleurotus ostreatus, and Coprinus aratus K. S. JAUHRI
Summary The amino acid content of the three fungi, viz., Rhizoctonia melongina, Pleurotus ostreatus, and Coprinus aratus, grown in liquid media (JAUHRI and SEN 1978d) containing agricultural wastes (sugarcane bagasse for the former two and wheat straw for the latter), were analysed qualitatively. Amino acid fraction of the three fungi, determined through paper chromatography, contained all the 8 essential amino acids in addition to 9 odd amino acids, except in the case of Rhizoctonia melongina in which the essential amino acid lysine was lacking. The possibilities for mass production and the use of these three fungi in dietetics are further discussed in this paper.
Zusammenfassung Rhizoctonia melongina, Pleurotus ostreatus und Coprinus aratus, die in einem flussigen Medium mit landwirtschaftlichen Abfallen (Zuckerrohrtreber fur Ph. melongina und P. ostreatus und Weizenstroh fur C. aratus) kultiviert worden waren, wurden einer Qualitatsanalyse unterzogen. Die Aminosaurefraktion der drei Pilze enthielt aIle acht essentiellen Aminosauren, nur bei Rh. melongina fehlte die essentielle Aminosaure Lysin. Moglichkeiten der industriemal3igen Produktion und Verwendung in der Diatetik werden besprochen.
The amino acid composition of the fungal mycelium is of greater significance, from the standpoint of its potential nutritional value, than merely the protein content determined by nitrogen analysis (LITCHFIELD 1968). Assuming good digestibility, the value of fungal protein is determined by its amino acid composition. The amino acid composition of yeast and some other fungi can favourably be compared with casein or meat with respect to their amino acids (ROSE 1937). Many investigations have listed the amino acid composition of some important edible fungi (SEELKOPF and SCHUSTER 1957, REUSSER et al. 1958, YAKOHATA and YAMACHI 1959, TOUZE 1961, ORILLO and CARANGAL 1961). Economic importance of fungal protein is evident from the fact that the efficiency of protein production from a given quantity of carbohydrate in mushrooms and other higher fungi is about 65 per cent as compared with about 20 per cent for pork, 15 per cent for milk, 5 per cent for poultry, and 4 per cent for beef (ROBINSON and DAVIDSON 1959). After standardizing the optimum physical and chemical factors (JAUHRI et al. 1978, JAUHRI and SEN 1978a, b, c, d) for growing these fungi on their respective modified media, an attempt was made to analyse qualitatively their amino acid content to explore the possibilities of growing them on a mass-scale for use in dietetics.
620
K. S.
JAUHRI
Materials and Methods Rhizoctonia melongina, Pleurotus ostreatus, and Coprinus aratus were grown in their respective stuffed media under as optimum conditions (JAUHRI et al. 1978, JAUHRI and SEN 1978a, b, c, d) as possible. 'The mycelial mat was harvested and separated from the residual substrate. After separation and washing, the mat and the filtrate were dried individually and analysed for their amino acid content. The qualitative analysis of amino acids was done by paper chromatography. The methods used for analysing the amino acids of the three fungi by chromatography were the same as given by BANO et al. (1963).
Results and Discussion Many of the earlier studies on the nutritive value and composition of several species of mushrooms and other fungi (BARES 1927, GUDLET 1933, KIZEL and KONOVALOV 1937) as well as investigations by LINTZEL (1941), FITZPATRIC et al. (1946), and ESSENLEN and FELLERS (1946), have shown that, in addition to their flavour, in several other properties proteins of some mushrooms are almost similar to muscle protein. Through qualitative and quantitative analysis of amino acid content of protein from Rhizoctonia solani, CHAHAL (1969) reported that all the essential amino acids are present in sufficient amounts as compared to those of other stable foods like wheat and rice. He has also shown that the amino acid composition is very much comparable to that of meat. It is very interesting to note that the three fungi tested in this study were found to have most of the essential amino acids (including those containing sulpher). Except in the case of R. melongina, deficient in lysine, no addition of any other amino acids is required in the case of P. ostreatus and O. aratus (Table 1). ROSE (1937) also found mushrooms to be superior when that portion of essential amino acids required for satisfactory mammalian growth is compared. CLARK et al. (1964) reported that the wild Ooprinus species accumulated large amounts of cystothionine which can form methionine as well as cystine, thus further confirming that Ooprinus species contain sufficient amounts of methionine. But in contrast to this is LITCHFIELD'S 1968) observation that mushrooms and higher fungi are deficient in sulpher-containing amino acids. Also BANO et al. (1963) made similar observations in the case of Table 1. Range ofamino acids detected in the mycelium of Rhizoctonia melongina, Pleurotus ostreatus, and Coprinus amtus Amino acids Alanine Arginine Asparagine Cystine Glutamine Glycine Histidine Hydroxy proline Leucine Lysine Methionine p-Phenyl-alanine Threonine Tryptophan Tyrosine Valine Unknown
R. melongina P. ostreatus
C. aratus
R. melongina P. ostreatus
+
+ +
+
+
+
+
+
+
+ +
+ + + +
+ + ++ + + + +
+ + + + + + + +
+ + + + +
+
+
+ + + + + + + + + + + + +2
+ + + + + + + + + + + + +2
+ + +
+
+1
+ + + + + + +2
C. aratus
Production of Protein by Fungi from Agricultural Wastes. VI.
621
Pleurotus flabellatus, but they suggested that the deficiency can be corrected by the addition of sulpher-containing amino acids like phenylalanine and methionine. There are a number of factors that determine the usefulness of a protein as a source of nutrition for man and animals. The more important of these are the nutritional value, cost at which it is delivered to the consumers, and their acceptibility (LITCHFIELD 1968). Of the three fungi tested, Pleurotus ostreatus and Coprinus aratus are known as edible mushrooms and Rhizoctonia melongina as a cellulolytic fungus. All the three fungi have been shown to compete successfully with other fungi on undecomposed sugarcane bagasse or wheat straw and can be cultivated at temperatures ranging from 27 to 35 °0 (JAUHRI et al. 1978). Secondly, the fact they can be cultivated within a period of two weeks, offers great possibilities for their large-scale production and application in dietetics. In summing up, it is important to point out that, in making use of waste materials, it is imperative to know the cost involved for collection, transportation, storage, pretreatment etc. LITCHFIELD (1968), from a study on the economy of the utilization of waste material, observed the cost involved to be prohibitive for mushroom cultivation. On the contrary, the present investigations indicate that in an agricultural country like India where most of the waste material finds only uneconomic utilization, if at all, the cost involved is negligible and in a well planned out system these efforts are sure to prove highly economical, especially when the substances do not require any pretreatment like hydrolysis. A study of physical factors controlling protein production by the three fungi indicates the importance of the factors, such as temperature, which is invariably one of the limiting factors barring large-scale production. Perusal of literature shows lack of definite information on this score. An ideal condition for the tropics would be a range of growth temperatures from 45-50 °0 which does not require an elaborate cooling system in fermentors. But as such an ideal organism has not yet been reported, one has to be satisfied even with an organism preferring a temperature of 35 °0 as in the case of R. melongina and C. aratus (JAUHRI et al. 1978). Special attention is to be centered on the influence of various metallic ions, because undue addition of these tends to develop bitter flavour in the mycelium (HUMFELD and SUGHIHARA 1952). It is, therefore, important to limit the levels of inorganic salts in a medium which ensures palatability of mycelium with good growth and protein production (JAUHRI and SEN 1978c). Inspite of all advantages involved in the economy of conversion of carbohydrates to protein by fungi, one important drawback could be the extremely large quantities of water that would be needed for cultivating the fungus, washing and converting it into a commercial product. Exclusive feeding trials would naturally have to be conducted to assure the beneficial effect of the fungal protein on the system of animals and subsequently of man. References BANo, Z., SRINIVASAN, K. S., and SRIVASTAVA, R. C.: Appl. Microbiol. II (1963), 184. BARES, J.: Chern. Listy. 21 (1927), 477. CHAHAL, D. S.: Agric. Agro-Industr. J. 2 (12) (1969), 33. CLARK, ERICA, and ROWBURY, R. J.: J. Gen. Microbiol. 36 (3) (1964), 333. ESSENLEN, W. B. JR., and FELLERS, C. R.: Mass. Agric. Exper. Sta. Bull. No. 434 (1946). FITZPATRIC, R., ESSENLEN, W. B. Jr., and WEIR, E.: J. Amer. Diet. Ass. 22 (1946), 318. GUDLET, M. A.: Schriften Zentral. Forschungsinst. Lebensmittelchem. (USSR) 4 (1933), 8. RUMFELD, R., and SUGHIHARA, T. F.: Mycologia 44 (1952),605. 41 ZbI. Bakt. II. Abt., Bd. 133
622
K. S. JAUHRI, Production of Protein by Fungi from Agricultural Wastes. VI.
JAUHRI, K. S., LAKSHMI KUMARI, M., and SEN, A.: Zbl. Bakt. II 133 (1978),588-696. and SEN, A.: Zbl. Bakt. II 133 (1978a), 597-603. Zbl. Bakt. II 133 (1978b), 604-608. - Zbl. Bakt. II 133 (1978c), 609- 613. - Zbl. Bakt. II 133 (1978d), 614--618. KIZEL, A., and KONOVALOV, S.: Biokhimiya 2 (1937), 47. LINTZEL, W.: Biochem. Z. 308 (1941), 413. LITCHFIELD, J. H.: Single-cell protein (MATELES and TANNENBAUM, eds.). M.LT. Press, London 1968, 309. ORILLO, C. A., and CARANGAL, A. R. Jr.: Philippine Agriculturist 45 (1961), 29. REUSSER, F., SPENCER, J. F. T., and SALLANS, H. R.: Appl. Microbiol. 6 (5) (1958),81. ROSE, W. C.: Science 86 (1937), 298. SEELKOPF, C., and SCHUSTER, H.: Wichtige Speisepilze. Z. Unters. Lebensmitt. 106 (1957), 177. TOUZE, J. M.: Compt. Rend. 252 (1961), 208. YOKOHATA, A., and YAMACHI, K.: Hiroshima Agr. ColI. Bull. 1 (1959), 19. Author's address: Dr. K. S. JAUHRI, Division of Microbiology, Indian Agricultural Research Institute, New Delhi· 110012, India.
[Division of Microbiology, Indian Agricultural Research Institute, New Delhi, India]
Production of Protein by Fungi from Agricultural Wastes VI. Quality of the Protein Formed in Rhizoctonia melongina, Pleurotus ostreatus, and Coprinus aratus K. S. JAUHRI
Summary The amino acid content of the three fungi, viz., Rhizoctonia melongina, Pleurotus ostreatus, and Coprinus aratus, grown in liquid media (JAUHRI and SEN 1978d) containing agricultural wastes (sugarcane bagasse for the former two and wheat straw for the latter), were analysed qualitatively. Amino acid fraction of the three fungi, determined through paper chromatography, contained all the 8 essential amino acids in addition to 9 odd amino acids, except in the case of Rhizoctonia melongina in which the essential amino acid lysine was lacking. The possibilities for mass production and the use of these three fungi in dietetics are further discussed in this paper.
Zusammenfassung Rhizoctonia melongina, Pleurotus ostreatus und Coprinus aratus, die in einem flussigen Medium mit landwirtschaftlichen Abfallen (Zuckerrohrtreber fur Ph. melongina und P. ostreatus und Weizenstroh fur C. aratus) kultiviert worden waren, wurden einer Qualitatsanalyse unterzogen. Die Aminosaurefraktion der drei Pilze enthielt aIle acht essentiellen Aminosauren, nur bei Rh. melongina fehlte die essentielle Aminosaure Lysin. Moglichkeiten der industriemal3igen Produktion und Verwendung in der Diatetik werden besprochen.
The amino acid composition of the fungal mycelium is of greater significance, from the standpoint of its potential nutritional value, than merely the protein content determined by nitrogen analysis (LITCHFIELD 1968). Assuming good digestibility, the value of fungal protein is determined by its amino acid composition. The amino acid composition of yeast and some other fungi can favourably be compared with casein or meat with respect to their amino acids (ROSE 1937). Many investigations have listed the amino acid composition of some important edible fungi (SEELKOPF and SCHUSTER 1957, REUSSER et al. 1958, YAKOHATA and YAMACHI 1959, TOUZE 1961, ORILLO and CARANGAL 1961). Economic importance of fungal protein is evident from the fact that the efficiency of protein production from a given quantity of carbohydrate in mushrooms and other higher fungi is about 65 per cent as compared with about 20 per cent for pork, 15 per cent for milk, 5 per cent for poultry, and 4 per cent for beef (ROBINSON and DAVIDSON 1959). After standardizing the optimum physical and chemical factors (JAUHRI et al. 1978, JAUHRI and SEN 1978a, b, c, d) for growing these fungi on their respective modified media, an attempt was made to analyse qualitatively their amino acid content to explore the possibilities of growing them on a mass-scale for use in dietetics.
620
K. S.
JAUHRI
Materials and Methods Rhizoctonia melongina, Pleurotus ostreatus, and Coprinus aratus were grown in their respective stuffed media under as optimum conditions (JAUHRI et al. 1978, JAUHRI and SEN 1978a, b, c, d) as possible. 'The mycelial mat was harvested and separated from the residual substrate. After separation and washing, the mat and the filtrate were dried individually and analysed for their amino acid content. The qualitative analysis of amino acids was done by paper chromatography. The methods used for analysing the amino acids of the three fungi by chromatography were the same as given by BANO et al. (1963).
Results and Discussion Many of the earlier studies on the nutritive value and composition of several species of mushrooms and other fungi (BARES 1927, GUDLET 1933, KIZEL and KONOVALOV 1937) as well as investigations by LINTZEL (1941), FITZPATRIC et al. (1946), and ESSENLEN and FELLERS (1946), have shown that, in addition to their flavour, in several other properties proteins of some mushrooms are almost similar to muscle protein. Through qualitative and quantitative analysis of amino acid content of protein from Rhizoctonia solani, CHAHAL (1969) reported that all the essential amino acids are present in sufficient amounts as compared to those of other stable foods like wheat and rice. He has also shown that the amino acid composition is very much comparable to that of meat. It is very interesting to note that the three fungi tested in this study were found to have most of the essential amino acids (including those containing sulpher). Except in the case of R. melongina, deficient in lysine, no addition of any other amino acids is required in the case of P. ostreatus and O. aratus (Table 1). ROSE (1937) also found mushrooms to be superior when that portion of essential amino acids required for satisfactory mammalian growth is compared. CLARK et al. (1964) reported that the wild Ooprinus species accumulated large amounts of cystothionine which can form methionine as well as cystine, thus further confirming that Ooprinus species contain sufficient amounts of methionine. But in contrast to this is LITCHFIELD'S 1968) observation that mushrooms and higher fungi are deficient in sulpher-containing amino acids. Also BANO et al. (1963) made similar observations in the case of Table 1. Range ofamino acids detected in the mycelium of Rhizoctonia melongina, Pleurotus ostreatus, and Coprinus amtus Amino acids Alanine Arginine Asparagine Cystine Glutamine Glycine Histidine Hydroxy proline Leucine Lysine Methionine p-Phenyl-alanine Threonine Tryptophan Tyrosine Valine Unknown
R. melongina P. ostreatus
C. aratus
R. melongina P. ostreatus
+
+ +
+
+
+
+
+
+
+ +
+ + + +
+ + ++ + + + +
+ + + + + + + +
+ + + + +
+
+
+ + + + + + + + + + + + +2
+ + + + + + + + + + + + +2
+ + +
+
+1
+ + + + + + +2
C. aratus
Production of Protein by Fungi from Agricultural Wastes. VI.
621
Pleurotus flabellatus, but they suggested that the deficiency can be corrected by the addition of sulpher-containing amino acids like phenylalanine and methionine. There are a number of factors that determine the usefulness of a protein as a source of nutrition for man and animals. The more important of these are the nutritional value, cost at which it is delivered to the consumers, and their acceptibility (LITCHFIELD 1968). Of the three fungi tested, Pleurotus ostreatus and Coprinus aratus are known as edible mushrooms and Rhizoctonia melongina as a cellulolytic fungus. All the three fungi have been shown to compete successfully with other fungi on undecomposed sugarcane bagasse or wheat straw and can be cultivated at temperatures ranging from 27 to 35 °0 (JAUHRI et al. 1978). Secondly, the fact they can be cultivated within a period of two weeks, offers great possibilities for their large-scale production and application in dietetics. In summing up, it is important to point out that, in making use of waste materials, it is imperative to know the cost involved for collection, transportation, storage, pretreatment etc. LITCHFIELD (1968), from a study on the economy of the utilization of waste material, observed the cost involved to be prohibitive for mushroom cultivation. On the contrary, the present investigations indicate that in an agricultural country like India where most of the waste material finds only uneconomic utilization, if at all, the cost involved is negligible and in a well planned out system these efforts are sure to prove highly economical, especially when the substances do not require any pretreatment like hydrolysis. A study of physical factors controlling protein production by the three fungi indicates the importance of the factors, such as temperature, which is invariably one of the limiting factors barring large-scale production. Perusal of literature shows lack of definite information on this score. An ideal condition for the tropics would be a range of growth temperatures from 45-50 °0 which does not require an elaborate cooling system in fermentors. But as such an ideal organism has not yet been reported, one has to be satisfied even with an organism preferring a temperature of 35 °0 as in the case of R. melongina and C. aratus (JAUHRI et al. 1978). Special attention is to be centered on the influence of various metallic ions, because undue addition of these tends to develop bitter flavour in the mycelium (HUMFELD and SUGHIHARA 1952). It is, therefore, important to limit the levels of inorganic salts in a medium which ensures palatability of mycelium with good growth and protein production (JAUHRI and SEN 1978c). Inspite of all advantages involved in the economy of conversion of carbohydrates to protein by fungi, one important drawback could be the extremely large quantities of water that would be needed for cultivating the fungus, washing and converting it into a commercial product. Exclusive feeding trials would naturally have to be conducted to assure the beneficial effect of the fungal protein on the system of animals and subsequently of man. References BANo, Z., SRINIVASAN, K. S., and SRIVASTAVA, R. C.: Appl. Microbiol. II (1963), 184. BARES, J.: Chern. Listy. 21 (1927), 477. CHAHAL, D. S.: Agric. Agro-Industr. J. 2 (12) (1969), 33. CLARK, ERICA, and ROWBURY, R. J.: J. Gen. Microbiol. 36 (3) (1964), 333. ESSENLEN, W. B. JR., and FELLERS, C. R.: Mass. Agric. Exper. Sta. Bull. No. 434 (1946). FITZPATRIC, R., ESSENLEN, W. B. Jr., and WEIR, E.: J. Amer. Diet. Ass. 22 (1946), 318. GUDLET, M. A.: Schriften Zentral. Forschungsinst. Lebensmittelchem. (USSR) 4 (1933), 8. RUMFELD, R., and SUGHIHARA, T. F.: Mycologia 44 (1952),605. 41 ZbI. Bakt. II. Abt., Bd. 133
622
K. S. JAUHRI, Production of Protein by Fungi from Agricultural Wastes. VI.
JAUHRI, K. S., LAKSHMI KUMARI, M., and SEN, A.: Zbl. Bakt. II 133 (1978),588-696. and SEN, A.: Zbl. Bakt. II 133 (1978a), 597-603. Zbl. Bakt. II 133 (1978b), 604-608. - Zbl. Bakt. II 133 (1978c), 609- 613. - Zbl. Bakt. II 133 (1978d), 614--618. KIZEL, A., and KONOVALOV, S.: Biokhimiya 2 (1937), 47. LINTZEL, W.: Biochem. Z. 308 (1941), 413. LITCHFIELD, J. H.: Single-cell protein (MATELES and TANNENBAUM, eds.). M.LT. Press, London 1968, 309. ORILLO, C. A., and CARANGAL, A. R. Jr.: Philippine Agriculturist 45 (1961), 29. REUSSER, F., SPENCER, J. F. T., and SALLANS, H. R.: Appl. Microbiol. 6 (5) (1958),81. ROSE, W. C.: Science 86 (1937), 298. SEELKOPF, C., and SCHUSTER, H.: Wichtige Speisepilze. Z. Unters. Lebensmitt. 106 (1957), 177. TOUZE, J. M.: Compt. Rend. 252 (1961), 208. YOKOHATA, A., and YAMACHI, K.: Hiroshima Agr. ColI. Bull. 1 (1959), 19. Author's address: Dr. K. S. JAUHRI, Division of Microbiology, Indian Agricultural Research Institute, New Delhi· 110012, India.