Growth in YM Broth: After 5 days at 17° C, the vegetative cells are oval or ellipsoidal, 2.5-4.5 x 5.0-6.0 µm, single or in pairs, and septated hyphal cells are present (Fig. 4A). After one month at 17° C, an incomplete ring and a sediment are present.
Growth on YM agar: After one month at 17° C, the streak culture is pinkish-cream, smooth, dull-shining, butyrous, and has an entire margin. Dalmau plate culture on corn meal agar: A few mycelia are formed.
Ballistospores: Ballistospores are produced on corn meal agar and YM agar. They are globose, napiform or ampulliform, 2.0-3.5 x 2.5-4.0 pm (Fig. 4B).
Fermentation: Negative.

Maximum growth temperature: 28-29° C. Vitamins required: Thiamine. Growth on 50% (w/w) glucose-yeast extract agar: Negative.
Production of starch-like substances: Negative.
Liquefaction of gelatin: Negative.
Acid production on chalk agar: Negative.
Splitting of fat: Negative.
Urease: Positive.
Diazonium blueB reaction: Positive.
G + C content of nuclear DNA: 41.7-42.3 mol% (by HPLC), 39.1-41.0 mol% (from 7in) (Table 3).
Major ubiquinone: Q-10 (Table 4).
Xylose in the cells: Present.
Strains examined: The strain NZ-44, which was isolated from a dead leaf of Nothofagus fusca at Kaimanawa State Forest Park, Taupo, New Zealand in 1987, is the type strain of the species. This strain is deposited at the Japan Collection of Microorganisms, Wako, Saitama, as JCM 8934. The other strains NZ-64 and NZ-87 are also deposited in the Japan Collection of Microorganisms, as JCM 8935 and JCM 8938, respectively.
B. mrakii has a close resemblance to B. aumntiaca and B. dendrophila in its biochemical and physiological characters. However, the differences were found between B. mrakii and the latter two species in DNA dissimilarity as deduced from DNA binding experiments (5-13%) (Table 7). Practically, it can be distinguished from the latter two species in its assimilation of melibiose, raffinose and nitrate (Table 8).

In liquid YM post dies 5 ad 17° C, cellulae vegeta-tivae ovoideae vel ellipsoideae, 2.5-4.5 x 5.0-6.0 pm, singulae aut binae. Post unum mensem ad 17° C, anulus imperfecta et sedimentum formantur. Cultura in agaro YM, cremea vel subrosea, glabra, partimdura, butyracea et margine glabra. Ballistosporae rotundae, napiformes vel ampulliformes, 2.0-3.5 x 2.5-4.0 pm. Mycelium formantur. Fermentatio nulla. GIu-cosum, galactosum, L-sorbosum (lente et exiguum, vel nullum), saccharosum, maltosum, cellobiosum, tre-halosum, lactosum (lente vel exiguum, vel nullum), melibiosum, raffinosum, melezitosum, amylum sol¬ubile, D-xylosum, L-arabinosum, D-arabinosum, D-ribosum, L-rhamnosum, erythritolum (exiguum vel nullum), galactitolum (lente et exiguum, vel nullum), D-mannitolum (lente), D-glucitolum (exiguum vel nul¬lum), a-methyl-D-glucosidum, salicinum, glucono-6-lactonum, acidum 2-ketogluconicum, acidum 5-ketogluconicum, acidum DL-lacticum acidum (exiguum, vel lente et exiguum), acidum succinicum, citricum (exiguum) et inositolum assimilantur, at non inulinum, ethanolum, glycerolum nec ribitolum. Kali-um nitricum non assimilatur. Maxima temperatura crescentiae: 28-29° C. Ad crescentiam thiaminum necessarium est. Proportio molaris guanini + cytosi-ni in acido deoxyribonucleico: 41.7-42.3 mol% (per HPLC), 39.1-41.0 mol% (ex 7m). Ubiquinonum majus: Q-10. Xylosum in cellulis presens.
Holotypus: JCM 8934 (originaliter ut NZ-44).