Fungal hydrophobins as predictors of the gushing activity of barley and malt

Tuija Sarlin, Markus Linder, Tiina Nakari-Setälä, Merja Penttilä, Erja Kotaviita, Juhani Olkku, Auli Haikara

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

Abstract

Hydrophobins are small, moderately hydrophobic proteins produced by filamentous fungi. Hydrophobins have been found on the cell walls of hyphae and on spore surfaces, but they can also be secreted into the culture medium. The characteristic feature of these surface-active proteins is their ability to self-assemble at hydrophilic/hydrophobic interfaces forming amphipathic membranes. This property allows hydrophobins to fulfil a broad spectrum of functions in fungal growth and development. It has been established that hydrophobins are able to stabilize air bubbles and oil droplets in water. Our studies have indi-cated that hydrophobins also act as gushing factors of beer. As reported earlier, we were able to isolate hydrophobins from mycelium and culture broths of gushing active fungi. The proteins were purified by reverse-phase chromatography. Their ability to cause gushing was studied by adding pure protein into beer bottles and by rocking the bottles for three days. After opening the bottles, the amount of overfoaming beer was measured. Already very small amounts of hydrophobins, at the level of micrograms, were found to cause gush ing. Polyclonal antibodies against the hydrophobin of Fusarium poae were raised in rabbits. An immunological ELISA-method for detection of hydrophobins in barley and malt was developed. Malt samples were analyzed with the developed ELISA method, and the results were com-pared to the gushing test, where an aqueous extract of malt was added to bottled beer and the bottles were rocked for three days, as well as to the deoxynivalenol (DON) content of the samples. The results of the hydrophobin-ELISA test were observed to correlate with the gushing potential of the malt. According to data obtained from gushing positive and negative samples, a tentative gushing limit absorbance value, which can be used for prediction of the gushing activity of barley and malt, was set. Correlation was not found between the gushing potential and the DON content of malt or between the amount of hydrophobins and DON in malt. We also measured hydrophobin levels at different stages of a lab-scale mashing process. We observed that hydrophobins ended up in the wort, although they were also detected in spent grains and trub. The hydrophobin-ELISA method has also been applied to detection of hydrophobins in different beverages and raw materials.
Original languageEnglish
Title of host publicationASBC Newsletter
Volume63
Publication statusPublished - 2003
MoE publication typeB3 Non-refereed article in conference proceedings
EventASBC Annual Meeting - Santa Ana Pueblo, United States
Duration: 7 Jun 200311 Jun 2003

Seminar

SeminarASBC Annual Meeting
CountryUnited States
CitySanta Ana Pueblo
Period7/06/0311/06/03

Fingerprint

malt
barley
beers
bottles
deoxynivalenol
enzyme-linked immunosorbent assay
hydrophobins
proteins
Fusarium poae
spent grains
mashing
wort (brewing)
malt extract
fungi
reversed-phase liquid chromatography
bubbles
polyclonal antibodies
sampling
beverages
hyphae

Cite this

Sarlin, T., Linder, M., Nakari-Setälä, T., Penttilä, M., Kotaviita, E., Olkku, J., & Haikara, A. (2003). Fungal hydrophobins as predictors of the gushing activity of barley and malt. In ASBC Newsletter (Vol. 63). [PB15]
Sarlin, Tuija ; Linder, Markus ; Nakari-Setälä, Tiina ; Penttilä, Merja ; Kotaviita, Erja ; Olkku, Juhani ; Haikara, Auli. / Fungal hydrophobins as predictors of the gushing activity of barley and malt. ASBC Newsletter. Vol. 63 2003.
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abstract = "Hydrophobins are small, moderately hydrophobic proteins produced by filamentous fungi. Hydrophobins have been found on the cell walls of hyphae and on spore surfaces, but they can also be secreted into the culture medium. The characteristic feature of these surface-active proteins is their ability to self-assemble at hydrophilic/hydrophobic interfaces forming amphipathic membranes. This property allows hydrophobins to fulfil a broad spectrum of functions in fungal growth and development. It has been established that hydrophobins are able to stabilize air bubbles and oil droplets in water. Our studies have indi-cated that hydrophobins also act as gushing factors of beer. As reported earlier, we were able to isolate hydrophobins from mycelium and culture broths of gushing active fungi. The proteins were purified by reverse-phase chromatography. Their ability to cause gushing was studied by adding pure protein into beer bottles and by rocking the bottles for three days. After opening the bottles, the amount of overfoaming beer was measured. Already very small amounts of hydrophobins, at the level of micrograms, were found to cause gush ing. Polyclonal antibodies against the hydrophobin of Fusarium poae were raised in rabbits. An immunological ELISA-method for detection of hydrophobins in barley and malt was developed. Malt samples were analyzed with the developed ELISA method, and the results were com-pared to the gushing test, where an aqueous extract of malt was added to bottled beer and the bottles were rocked for three days, as well as to the deoxynivalenol (DON) content of the samples. The results of the hydrophobin-ELISA test were observed to correlate with the gushing potential of the malt. According to data obtained from gushing positive and negative samples, a tentative gushing limit absorbance value, which can be used for prediction of the gushing activity of barley and malt, was set. Correlation was not found between the gushing potential and the DON content of malt or between the amount of hydrophobins and DON in malt. We also measured hydrophobin levels at different stages of a lab-scale mashing process. We observed that hydrophobins ended up in the wort, although they were also detected in spent grains and trub. The hydrophobin-ELISA method has also been applied to detection of hydrophobins in different beverages and raw materials.",
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Sarlin, T, Linder, M, Nakari-Setälä, T, Penttilä, M, Kotaviita, E, Olkku, J & Haikara, A 2003, Fungal hydrophobins as predictors of the gushing activity of barley and malt. in ASBC Newsletter. vol. 63, PB15, ASBC Annual Meeting, Santa Ana Pueblo, United States, 7/06/03.

Fungal hydrophobins as predictors of the gushing activity of barley and malt. / Sarlin, Tuija; Linder, Markus; Nakari-Setälä, Tiina; Penttilä, Merja; Kotaviita, Erja; Olkku, Juhani; Haikara, Auli.

ASBC Newsletter. Vol. 63 2003. PB15.

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

TY - GEN

T1 - Fungal hydrophobins as predictors of the gushing activity of barley and malt

AU - Sarlin, Tuija

AU - Linder, Markus

AU - Nakari-Setälä, Tiina

AU - Penttilä, Merja

AU - Kotaviita, Erja

AU - Olkku, Juhani

AU - Haikara, Auli

PY - 2003

Y1 - 2003

N2 - Hydrophobins are small, moderately hydrophobic proteins produced by filamentous fungi. Hydrophobins have been found on the cell walls of hyphae and on spore surfaces, but they can also be secreted into the culture medium. The characteristic feature of these surface-active proteins is their ability to self-assemble at hydrophilic/hydrophobic interfaces forming amphipathic membranes. This property allows hydrophobins to fulfil a broad spectrum of functions in fungal growth and development. It has been established that hydrophobins are able to stabilize air bubbles and oil droplets in water. Our studies have indi-cated that hydrophobins also act as gushing factors of beer. As reported earlier, we were able to isolate hydrophobins from mycelium and culture broths of gushing active fungi. The proteins were purified by reverse-phase chromatography. Their ability to cause gushing was studied by adding pure protein into beer bottles and by rocking the bottles for three days. After opening the bottles, the amount of overfoaming beer was measured. Already very small amounts of hydrophobins, at the level of micrograms, were found to cause gush ing. Polyclonal antibodies against the hydrophobin of Fusarium poae were raised in rabbits. An immunological ELISA-method for detection of hydrophobins in barley and malt was developed. Malt samples were analyzed with the developed ELISA method, and the results were com-pared to the gushing test, where an aqueous extract of malt was added to bottled beer and the bottles were rocked for three days, as well as to the deoxynivalenol (DON) content of the samples. The results of the hydrophobin-ELISA test were observed to correlate with the gushing potential of the malt. According to data obtained from gushing positive and negative samples, a tentative gushing limit absorbance value, which can be used for prediction of the gushing activity of barley and malt, was set. Correlation was not found between the gushing potential and the DON content of malt or between the amount of hydrophobins and DON in malt. We also measured hydrophobin levels at different stages of a lab-scale mashing process. We observed that hydrophobins ended up in the wort, although they were also detected in spent grains and trub. The hydrophobin-ELISA method has also been applied to detection of hydrophobins in different beverages and raw materials.

AB - Hydrophobins are small, moderately hydrophobic proteins produced by filamentous fungi. Hydrophobins have been found on the cell walls of hyphae and on spore surfaces, but they can also be secreted into the culture medium. The characteristic feature of these surface-active proteins is their ability to self-assemble at hydrophilic/hydrophobic interfaces forming amphipathic membranes. This property allows hydrophobins to fulfil a broad spectrum of functions in fungal growth and development. It has been established that hydrophobins are able to stabilize air bubbles and oil droplets in water. Our studies have indi-cated that hydrophobins also act as gushing factors of beer. As reported earlier, we were able to isolate hydrophobins from mycelium and culture broths of gushing active fungi. The proteins were purified by reverse-phase chromatography. Their ability to cause gushing was studied by adding pure protein into beer bottles and by rocking the bottles for three days. After opening the bottles, the amount of overfoaming beer was measured. Already very small amounts of hydrophobins, at the level of micrograms, were found to cause gush ing. Polyclonal antibodies against the hydrophobin of Fusarium poae were raised in rabbits. An immunological ELISA-method for detection of hydrophobins in barley and malt was developed. Malt samples were analyzed with the developed ELISA method, and the results were com-pared to the gushing test, where an aqueous extract of malt was added to bottled beer and the bottles were rocked for three days, as well as to the deoxynivalenol (DON) content of the samples. The results of the hydrophobin-ELISA test were observed to correlate with the gushing potential of the malt. According to data obtained from gushing positive and negative samples, a tentative gushing limit absorbance value, which can be used for prediction of the gushing activity of barley and malt, was set. Correlation was not found between the gushing potential and the DON content of malt or between the amount of hydrophobins and DON in malt. We also measured hydrophobin levels at different stages of a lab-scale mashing process. We observed that hydrophobins ended up in the wort, although they were also detected in spent grains and trub. The hydrophobin-ELISA method has also been applied to detection of hydrophobins in different beverages and raw materials.

M3 - Conference article in proceedings

VL - 63

BT - ASBC Newsletter

ER -

Sarlin T, Linder M, Nakari-Setälä T, Penttilä M, Kotaviita E, Olkku J et al. Fungal hydrophobins as predictors of the gushing activity of barley and malt. In ASBC Newsletter. Vol. 63. 2003. PB15