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Analysis of Morphological Relationship Between Micro‐ and Macromorphology of Mortierella Species Using a Flow‐Through Chamber Coupled with Image Analysis
Author(s) -
PARK ENOCH Y.,
KOIZUMI KAYO,
HIGASHIYAMA KENICHI
Publication year - 2006
Publication title -
journal of eukaryotic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 1066-5234
DOI - 10.1111/j.1550-7408.2006.00094.x
Subject(s) - hypha , pellet , biology , mycelium , morphology (biology) , growth rate , botany , geometry , zoology , mathematics , genetics
. Using a flow‐through chamber coupled with image analysis, the morphological parameters of 11 Mortierella species were quantified, and the relationship between micro‐ and macromorphology was investigated. On potato‐dextrose‐agar plates, 5 species formed rose petal‐like colonies, 3 formed large round colonies, and 3 formed donut‐like colonies. By observing micromorphology in a flow‐through chamber, fungi were divided into 3 groups, classified according to morphological parameters: (i) a group with a high branch formation rate ( q b : tip/μm/h) and a low tip extension rate ( q tip : μm/tip/h); (ii) a group with a low branch formation rate and a high tip extension rate; and (iii) a group intermediate between the former and the latter groups. In suspension culture, group (i) fungi formed a hyphal bundle with a pulpy pellet‐like morphology and a pellet core. In contrast, group (ii) fungi showed an aggregation of hyphae without the pellet core. In a narrow‐specific hyphal growth rate (μ l ) range (0.35–0.45 h −1 ), a higher branch formation rate led to increased hyphal branching, resulting in the formation of a hyphal bundle with a pulpy pellet‐like morphology and a pellet core. When the branch formation rate was lower than 2 × 10 −3 tips/μm/h, the mycelia formed less branched but longer hypha. Our study surmises that a micromorphology consisting of a high hyphal growth rate (0.4 h −1 ), low tip extension rate (20 tips/μm/h), and high branch formation rate (8 × 10 −3 tips/μm/h) forms the suitable macromorphology for arachidonic acid production.