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The antagonism of Lambertella cornimaris to fungi and bacteria
[ 1°9 ]
THE ANTAGONISM OF LAMBERTELLA CORNIMARIS TO FUNGI AND BACTERIA By R. K. S. WOOD
Department
~f
Mycology and Plant Pathology, Imperial College, London, S. W. 7
Lambertella corni-maris grown on a variety of agar media is strongly antagonistic to Botrytis cinerea and to many other fungi and bacteria. The effect is not
attributed to pH change in the medium. The supernatant fluid from liquid cultures is also active, except against B. cinerea, where it has unexpectedly little effect on spore germination.
The fungus Lambertella corni-maris Hohnel was first found by von Hohnel ( 1 9 1 8) on mummified fruits of the cornelian cherry (Cornus masL.) in Austria. Further specimens were found in 1931 on mummified apples in Switzerland and on mummified pears at two places in south Germany (Harrison & el-Helaly, 1935). An isolate from Harrison's material was maintained for many years in the Imperial College Stock Culture Collection. During 1946 it was included among a wide range of fungi and other microorganisms which was tested for antagonism to Botrytis cinerea on agar media. The general results of these investigations has already been reported (Wood, 1951). In one series of tests, colonies of various organisms 20-25 mm. in diameter were established on plates of nutrient agar which were then sprayed with a suspension of spores of B. cinerea. The width of the zone about the colony in which spore germination was inhibited gave a rough measure of the antagonistic properties of the organisms. Rather surprisingly, Lambertella corni-maris was placed in the group showing greatest antagonism, zones of inhibition 20-25 mm. wide being obtained on glucose/peptone agar. Similar results were obtained on a variety of natural and synthetic media. The growth rate on all media tested was relatively low with an optimum about 20° C. and decreasing rapidly above 25 C. The pH of the agar below or immediately beyond actively growing hyphae was normally in the range 4'0-5'0. On certain media, particularly potato-glucose agar, clusters of orange-yellow crystals appeared in relatively large quantities in a zone 10-] 5 mm. wide about the colonies. Occasiunally, clusters or reddish coloured crystals also appeared. No attempt was made to isolate or identify these substances, preliminary experiments indicating that they were not very active antibiotics. In further tests colonies 20-25 mm. in diameter were established on potato-glucose agar. Suspensions of spores or mycelial fragments of a variety of organisms were streaked from the periphery of the plate to the edge of the colony. The following were tested in this way: 3 bacteria, 1 Actinomycete, 1 Zygomycete, 1 Oomycete, 11 Ascomycetes and 10 Fungi Imperfecti. The Zygomycete (Mucor hiemalis) grew to within 4 mm. of the edge of the colony. Growth of all others was inhibited in zones 10-30 111m. wide. C
110
Transactions British Mycological Society
The effect on bacteria was further investigated. The fungus was grown on a variety of agar and liquid media. Disks 11'0 mm. in diameter were cut from the agar immediately beyond colonies 20-25 mm. in diameter and placed in agar seeded with Staphylococcus aureus, Bacterium coli or Mycobacterium phlei. Similarly, 0'05 ml. of the various liquid media were placed in holes 11'0 mm. in diameter in seeded agar. After incubation for 48 hr. at 30° C. the zones of inhibition were observed. The general results were that natural media gave better growth and production of antibiotics than synthetic media, and that Bacterium coli was less affected than Staphylococcus aureus and Mycobacterium phlei which behaved similarly in these tests. Striking results were obtained in some cases, particularly with disks taken from potato-glucose or glucosepeptone cultures, zones 30-35 mm. in diameter being obtained with Staphylococcus aureus and Mycobacterium phlei and 18-20 mm. with Bacterium coli. These zones were streaked with bromthymol blue indicator after they had formed, and were always found to have a pH value in the range 7'0-7'5. It is unlikely therefore that they were a result of the low pH of the agar disks or the liquid media. Finally, it may be noted that while striking antagonism to Botrytis cinerea could always be demonstrated on agar cultures of the fungus, the supernatant fluid from liquid cultures had little or no effect on spore germination. The above summarizes observations made intermittently over a period of a few months, and are reported because records of antibiotic production by members of the Discomycetes are few and the results obtained were striking and somewhat unexpected. REFERENCES T. H. & EL-HELALY, A. F. (1935). On Lambertella corni-maris von Hohnel, a brown-spored parasitic Discomycete. Trans. Brit. mycol. Soc. 19, 199-2 14. HOHNEL, F. VON (1918). Lambertella. Fragm. z, Mykol. 21, no. 1078,47, WOOD, R. K. S. (1951). The control of diseases of lettuce by the use of antagonistic organisms. Ann. appl. Biol. 38, 203-216.
HARRISON,
(Accepted for publication 8 April 1952)
THE ANTAGONISM OF LAMBERTELLA CORNIMARIS TO FUNGI AND BACTERIA By R. K. S. WOOD
Department
~f
Mycology and Plant Pathology, Imperial College, London, S. W. 7
Lambertella corni-maris grown on a variety of agar media is strongly antagonistic to Botrytis cinerea and to many other fungi and bacteria. The effect is not
attributed to pH change in the medium. The supernatant fluid from liquid cultures is also active, except against B. cinerea, where it has unexpectedly little effect on spore germination.
The fungus Lambertella corni-maris Hohnel was first found by von Hohnel ( 1 9 1 8) on mummified fruits of the cornelian cherry (Cornus masL.) in Austria. Further specimens were found in 1931 on mummified apples in Switzerland and on mummified pears at two places in south Germany (Harrison & el-Helaly, 1935). An isolate from Harrison's material was maintained for many years in the Imperial College Stock Culture Collection. During 1946 it was included among a wide range of fungi and other microorganisms which was tested for antagonism to Botrytis cinerea on agar media. The general results of these investigations has already been reported (Wood, 1951). In one series of tests, colonies of various organisms 20-25 mm. in diameter were established on plates of nutrient agar which were then sprayed with a suspension of spores of B. cinerea. The width of the zone about the colony in which spore germination was inhibited gave a rough measure of the antagonistic properties of the organisms. Rather surprisingly, Lambertella corni-maris was placed in the group showing greatest antagonism, zones of inhibition 20-25 mm. wide being obtained on glucose/peptone agar. Similar results were obtained on a variety of natural and synthetic media. The growth rate on all media tested was relatively low with an optimum about 20° C. and decreasing rapidly above 25 C. The pH of the agar below or immediately beyond actively growing hyphae was normally in the range 4'0-5'0. On certain media, particularly potato-glucose agar, clusters of orange-yellow crystals appeared in relatively large quantities in a zone 10-] 5 mm. wide about the colonies. Occasiunally, clusters or reddish coloured crystals also appeared. No attempt was made to isolate or identify these substances, preliminary experiments indicating that they were not very active antibiotics. In further tests colonies 20-25 mm. in diameter were established on potato-glucose agar. Suspensions of spores or mycelial fragments of a variety of organisms were streaked from the periphery of the plate to the edge of the colony. The following were tested in this way: 3 bacteria, 1 Actinomycete, 1 Zygomycete, 1 Oomycete, 11 Ascomycetes and 10 Fungi Imperfecti. The Zygomycete (Mucor hiemalis) grew to within 4 mm. of the edge of the colony. Growth of all others was inhibited in zones 10-30 111m. wide. C
110
Transactions British Mycological Society
The effect on bacteria was further investigated. The fungus was grown on a variety of agar and liquid media. Disks 11'0 mm. in diameter were cut from the agar immediately beyond colonies 20-25 mm. in diameter and placed in agar seeded with Staphylococcus aureus, Bacterium coli or Mycobacterium phlei. Similarly, 0'05 ml. of the various liquid media were placed in holes 11'0 mm. in diameter in seeded agar. After incubation for 48 hr. at 30° C. the zones of inhibition were observed. The general results were that natural media gave better growth and production of antibiotics than synthetic media, and that Bacterium coli was less affected than Staphylococcus aureus and Mycobacterium phlei which behaved similarly in these tests. Striking results were obtained in some cases, particularly with disks taken from potato-glucose or glucosepeptone cultures, zones 30-35 mm. in diameter being obtained with Staphylococcus aureus and Mycobacterium phlei and 18-20 mm. with Bacterium coli. These zones were streaked with bromthymol blue indicator after they had formed, and were always found to have a pH value in the range 7'0-7'5. It is unlikely therefore that they were a result of the low pH of the agar disks or the liquid media. Finally, it may be noted that while striking antagonism to Botrytis cinerea could always be demonstrated on agar cultures of the fungus, the supernatant fluid from liquid cultures had little or no effect on spore germination. The above summarizes observations made intermittently over a period of a few months, and are reported because records of antibiotic production by members of the Discomycetes are few and the results obtained were striking and somewhat unexpected. REFERENCES T. H. & EL-HELALY, A. F. (1935). On Lambertella corni-maris von Hohnel, a brown-spored parasitic Discomycete. Trans. Brit. mycol. Soc. 19, 199-2 14. HOHNEL, F. VON (1918). Lambertella. Fragm. z, Mykol. 21, no. 1078,47, WOOD, R. K. S. (1951). The control of diseases of lettuce by the use of antagonistic organisms. Ann. appl. Biol. 38, 203-216.
HARRISON,
(Accepted for publication 8 April 1952)