Lactic acid production from molasses by mixed population of lactobacilli

Lactic acid production from molasses by mixed population of lactobacilli

Z bl. Ba k t. II. Abt. Bd. 134 (1979), 544- 546 [D epartm ent of Chemistry, U niver sit y of All ahabad, Allahabad, India] La ctic Acid Production f...

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Z bl. Ba k t. II. Abt. Bd. 134 (1979), 544- 546

[D epartm ent of Chemistry, U niver sit y of All ahabad, Allahabad, India]

La ctic Acid Production from Molasses by Mixed Population of La ctoba cilli K. P . TIWARI, ASHOK PANDEY, and NISHI l\1:ISHRA

Summary The production of lactic a ei d fr om mo la sses by mixed population s of (I) Lactobacillus bulqaricus AU (isolated from curd) and L. casei (supplied by NCL, Poona- S, I n dia) a n d (2) L. bulqari cus, L . delbruecki i (supplied by N CL , P oona- 8, India), and L. casei wa s stud ied . It has been found t h at a sso ciation of L. bulgaricus with L . casei slightly enhan ces t he yi el d of la ctic acid, while th e m ixed popula tion of L. bulqaricus, L . delbrueckii, and L. casei is as effec t ive as L. bulqaricus a lone .

Zusammenfassung D ie P r oduktion vo n Mil chsaure a us Melasse durch Mischpopulat ion cn 1. a us L actobacillus bulgaricus AU (iso liert a us Qua r k) und L . casei sowie 2. a us L . bulqaricus, L. delbrueckii 9649 (di eser St amm sow ie L . casei vo n N eL , Poona -S, I ndi en) und L. casei wurde u n te rsucht, D ie ers tgenannte Mischpopulat ion steigerte die Mi lchsaureb ildung leic ht, di e let ztgena nn te wir kte wie L . bul qaricus a lloin .

Lactic acid production from molasses by many lacti c acid bacteria has been st udied by several workers in batch and cont inuous fermentation (OSIPOV and OSIS (1963), 'I'rwsm a nd VYAS (1971, 1976), DEY a nd l\I ALAKAR (1944)). SEINEROVA and J EZKOVA (1964) reported that in st udying lacti c acid producti on by mixed cultures of lacti c acid bact eria or by those of lacti c acid ba ct eria with yeast , the combinat ion of L actobacillus aelbrueckii, L. casei , and S treptococcus have the most desira ble qualities. VEIKKO (1952, 1955) has shown symbiot ic relationship between different species of lactic acid bacteria in media of known chemical composition. BAUTISTA et al. (1966) id entified the compounds causing symbiotic growth of S. thermophilus and L. bulqaricus. BRANEN and KEENAN (1969) found that all lactobacilli strains, with the exc eption of L. casei, were significantly sti mulate d by a strain of S . ihermophilus. OBERMAN and ZDZISLAWA (1973) t est ed the gro wt h of mix ed p opul ation of L. casei and nisin. producing strain of S. lactis in batch and cont inuous ferment ation. TIWARI et al. found t hat associa tion of L. bulqaricu« with L. aelbrueckii ca uses marked enha nce ment in the yield of lact ic acid. F rom t he literature, it is clear t hat no work has been done on t he stu dy of lacti c acid fermentation from molasses by a mix ed growt h of (1) L . bulqaricus and L . casei an d (2) L. bulgaricus, L . casei and L. delbrueckii. Th erefore t he au thors t hought it desirable t o perform experiments for t he st udy of lacti c aci d produ ction from molasses in these mi xed populations of ba ct eria.

Lactic Acid Production from Molasses

545

Material and Method 900 g of molasses were diluted with two litres of distilled water and total volume was divided into 45 equal parts, each part being taken to 250 ml conical flask. The final volume in all these flasks was made 100 ml with distilled water. The flasks were plugged with non-absorbent cotton and sterilized at 15 Ib steam pressure in an autoclave for 30 minutes. The flasks were then cooled and divided into five sets, each consisting of nine flasks. Each set was subdivided into three subsets, each consisting of three flasks. First, second, and third sets were inoculated with 24-hour-old cultures of L. bulqoricus AU, L. delbrueckii 9649, and L. casei 7469, respectively. The fourth set was inoculated with L. bulqaricus and L. casei and the fifth set with equal amounts of the 24· -hour-old cultures of L. bulqaricus, L. casei, and L. delbrueckii. After inoculation, the flasks were incubated at 47° under frequent agitation. The pH of the mash was adjusted between 5.8 - 6.0 by gradual addition of CaC0 3 during the course of fermentation. The flasks were analyzed colorimetrically for lactic acid produced and sugar left unfermented after 2, 4, and 6 days of incubation.

Results The results of analysis are shown in Table 1. Table 1 S. Name of the strains No.

Incubation period in days

Yield of lactic acid gjlOO ml

gjlOO ml

1. L. bulqaricus AU

2 4 6

1.00 1.45 1.96

3.12 2.68 2.26

2. L. delbrueckii 9649

2 4 6

1.:31 2.57 2.55

2.82 2.10 1.57

3. L. casei 7469

2 4 6 2 4 6 2 4 6

0.99 1.48 1.75 1.11 1.80 2.01 1.06 1.60 1.96

3.15 2.67 2.50

4.

5.

L. bulqaricus L. caeei L. bulqaricus L. casei

+

L. delbrueckii

+ +

Sugar left

3.08 2.41 2.28 3.10 2.78 2.20

It is evident from Table 1 that L. bulgaricus AU, L. casei, and L. aelbrueckii individually fermented 44.55 %, 40.0 %, and 57.9 % of sugars into lactic acid, respectively. In mixed growth of L. bulgaricus and L. casei only a slight increase in the yield of lactic acid was obtained in comparison to the individual capacity of both strains. However, combination of L. bulgaricus with L. casei and L. aelbrueckii couId produce only 44.0 %lactic acid on the basis of total sugar, but the conversion on the basis of fermented sugar is 89.1 %, which is less than that produced by individual strains. The increase in yield of lactic acid by the first combination and failure by the second combination to give good results is probably due to the fermentative capacity of individual strains and different carbohydrate utilization by them. It appears from the results that L. casei stimulated the acid-producing activity of L. bulqarious, However, it also appears that in the second combination the strains interfered with the activity of one another.

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K. P. TIWARI, ASHOK PANDEY and NISHI MISHRA, Lactic Acid Production from Molasses

References BAUTISTA, E. S., DAHIYA, R. S., and SPECK, M. L.: J. Dairy Res. 33 (1966), 299-307. BRANEN, A. L., and KEENAN, T. W.: App!. Microbiol. 17 (1969), 280-185. DEY, N. C., and MALAKAR, M. C.: Science and Culture 9 (1944), 559. OBERMAN, H., and ZDZISLAWA, L.: Acta Microbiol. Polon., Ser. B: Microbiol. Appl. I) (1973), 151-161. OSIPOV, L., and OSIS, F.: Chern. Abstr. 59 (1963), 8092. TIWARI, H. K, and VYAS, S. R.: J. Res. Pundjab Agric. Univ. 8 (1971), 460-462. - - Indian J. Microbiol. 10 (1976),69-76. TIWARI, K. P., PANDEY, A., and MISHRA, N.: Proe. Natl. Aoad, Sci., India. 47A (1977),130-132. VEIKKO, NURMIKKO: Acta Chern. Scand. 6 (1952), 1258-1264. - Biol. Abstr. 29 (1955), 8826. Author's address: Dr. K. P. TIWARI, Dept. of Chemistry, University of Allahabad - 211 002, India,