Frequency of Occurrence of Fungi in the Glaciers

There are no reports in the literature on the frequency of occurrence of fungi in glacier ice, apart the infrequent sporadic isolations of individual fungal species, deposited by wind or snowfall into the ice [Abyzov, 1993; Ma et al., 1999, 2000; Price, 2000; Christner et al., 2003].

Table 2. Frequencies of occurrence of isolated Pénicillium species in Conwaybreen (C), Kongsvegen (K), and Austre Lovénbreen (A) glaciers

Pénicillium spp.

,. -i . Direct spreading of the sediment Filtration method (CFU L 1 ) -1 N

(CFU g )

C a

C b

K a

K b

K c

A a

C

K

A

P. bialowiezense d

88

161

11,280

410

160

P. brasilianum

2

P. brevicompactum d

3

14

2

P. chrysogenum d

2

48

65

828

26

P. commune d

7

548

25

P. corylophilum d

2

7

P. crustosum d

783

9000

552

1180

1720

1600

169

36

1

P. discolor d

10

248

2

P. echinulatum d

100

3

P. expansum d

105

P. glabrum d

42

20

10

1

P. lanosum d

26

1

P. nordicum d

10

5

1

P. olsonii d

42

40

P. palitans d

106

2

P. polonicum d

53

10

600

1

P. roqueforti d

40

P. solitum d

35

102

28

200

1

1

P. thomii d

550

58

P. tulipae

5

20

1

1

P. svalbardense d

43

200

60

15

Total

1059

9112

930

2480

13,000

4429

203

301

3

aClear glacial ice samples. Sediment rich glacial ice samples. cOutflow water samples

Penicillia isolated also on media with aw from 0.9 to 0.78.

aClear glacial ice samples. Sediment rich glacial ice samples. cOutflow water samples

Penicillia isolated also on media with aw from 0.9 to 0.78.

During our investigation ice from four different glaciers was sampled at the surface (supraglacial part), subglacial cavities and moulins, but primarily basal glacier ice (subglacial part) was sampled. The difference in spatial distribution along the sampled glaciers was observed as counts increased when supraglacial layers were compared with subglacial layers. In concordance, the non-melanized yeasts counts from the subglacial samples were two orders of magnitude greater when compared with those recovered from supraglacial samples (below 25 x 103 CFU L-1) [Butinar et al. , 2007] (Fig. 1). In general non-melanized yeasts predominated in clear glacial ice, although in samples of glacier ice with high gypsum inclusions, melanized yeast-like fungi prevailed (with CFU as high as 6 x 105 L-1) [Gunde-Cimerman et al., 2003]. A similar trend was observed also for penicillia [Sonjak et al., 2006]. Penicillia were in contrast with non-melanized and melanized yeast-like fungi primarily detected in sediment-rich subglacial ice (up to 9,2 x 103 CFU L-1) or subglacial meltwater (up to 13 x 103 CFU L-1) with mineral inclusions deriving from the glacier bed (Table 2) [Sonjak et al., 2006]. The counts of penicillia in the supraglacial samples were also considerably lower, only up to 50 CFU L-1 (Table 2) [Sonjak et al., 2006].

The highest fungal CFUs were in all cases obtained on media containing 5% NaCl (aw = 0.951), and 20% glucose (aw = 0.941) respectively [Gunde-Cimerman et al., 2003; Sonjak et al., 2006; Butinar et al., 2007]. Without salt and with salinity higher than 5%, the number of fungal CFU decreased. The upper salinity range for the detection of fungi was 24% NaCl with CFU values up to 5 CFU L-1 only. At lower salinities non-melanized yeasts dominated, but with increasing salinity the proportions changed in favour of melanized fungi a

Was this article helpful?

0 0

Post a comment