Characterization of an amphimull under Mediterranean evergreen oak forest (Quercus ilex): micromorphological and biodynamic descriptions

2008 ◽  
Vol 38 (2) ◽  
pp. 268-277 ◽  
Author(s):  
Simone Tagger ◽  
Claude Périssol ◽  
Stéven Criquet ◽  
Guy Aubert ◽  
Pierre Neville ◽  
...  

The relationships between microorganisms and microfauna were studied in an evergreen oak ( Quercus ilex L.) forest floor located in a French Mediterranean region characterized by hot and dry summers. The soil was a brown fersialitic soil with an amphimull, i.e., a mull with a thick litter. A micromorphological study of both litter and organomineral layers was used to observe relationships between white-rot fungi and fauna, such as oribatids, millipedes, enchytraeids, and earthworms. Microbiological properties of the litter and physicochemical properties of the soil were analysed. Enchytraeids comminute the faeces of other animals, whereas earthworms form aggregates. These two opposite actions probably modify aeration and water movements in deeper layers. Brown leaves and animal faeces constitute a nutritional substrate for white-rot fungi and other animals. Inside degraded cells of rootlets and bleached leaves, fungi form calcium oxalate crystals because the absorbent complex is saturated by an excess of calcium. Enzymes such as laccases, manganese peroxidases, cellulases, or xylanases were detected in the litter at significant levels. The high activity values of phosphatases in the litter could reflect a deficiency in available phosphorus. This deficiency could partly explain a low rate of litter degradation and the presence of an OH sublayer.

2013 ◽  
Vol 6 (4) ◽  
pp. 1154-1164 ◽  
Author(s):  
Ling-Ping Xiao ◽  
Zheng-Jun Shi ◽  
Yuan-Yuan Bai ◽  
Wei Wang ◽  
Xue-Ming Zhang ◽  
...  

1999 ◽  
Vol 45 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Makoto Ohkoshi ◽  
Atsushi Kato ◽  
Kentaro Suzuki ◽  
Noriko Hayashi ◽  
Mitsuro Ishihara
Keyword(s):  

2014 ◽  
Vol 50 (7) ◽  
pp. 730-736 ◽  
Author(s):  
O. I. Klein ◽  
N. A. Kulikova ◽  
E. V. Stepanova ◽  
O. I. Filippova ◽  
T. V. Fedorova ◽  
...  
Keyword(s):  

2010 ◽  
Vol 150 ◽  
pp. 181-181
Author(s):  
O. Salazar ◽  
I. Gajardo ◽  
A. Salinas ◽  
M. Vega ◽  
M.E. Lienqueo ◽  
...  

2016 ◽  
Vol 75 (2) ◽  
Author(s):  
. SISWANTO ◽  
. SUHARYANTO ◽  
Rossy FITRIA

SummaryOmphalina sp. a white-rot fungi (WRF)originated from oil palm plantation has abilityto degrade empty fruit bunches of oil palm(EFBOP) so that it is expected to producelaccase with high activity. The ability ofOmphalina sp. to produce laccase enzyme onliquid fermentation will be studied. The enzymewill also be partially purified andcharacterized. The research result showed thatthe highest enzyme activity (1.162 U/mL) wasobtained using glucose malt yeast (GMY)medium at room temperature for four days.The addition of 2,5-xylidine as an inducerproduced laccase earlier i.e two days, but theactivity of laccase was less active afterprolonged incubation compared to that ofcontrol. The laccase produced on mediumcontaining 2% EFBOP reached optimumactivity as much as 0.38 U/mL after 10 th daysof incubation. Partial purification of laccaseon Sephacryl S-200 HR column resulted58.23% of yield recovery with twice purity thanbefore. The optimum pH of laccase was 4.5.Laccase activity was stable even after heatedon 50 o C for 30 minutes, but then decreasedwhen heated until 60 o C. The laccase has K Mand V max as much as 0.15 mM and 0.56 U/mLrespectively.RingkasanOmphalina sp., adalah fungi pelapuk putih(FPP) hasil isolasi dari kebun kelapa sawityang diketahui mampu mendegradasi tandankosong kelapa sawit (TKKS) dengan cepatsehingga diharapkan mampu menghasilkanlakase dengan aktivitas tinggi. KemampuanOmphalina sp. menghasilkan enzim lakasepada fermentasi cair akan dipelajari. Selain itu,lakase yang dihasilkan akan dimurnikan secaraparsial serta dilakukan karakterisasi pH, suhu,dan konsentrasi substrat optimum. Hasilpenelitian menunjukkan bahwa Omphalina sp.menghasilkan lakase dengan aktivitas tertinggi(1,162 U/mL) pada medium glucose malt yeast(GMY) yang diinkubasikan pada suhu ruangselama empat hari. Penambahan 2,5-xilidinsebagai induser mempercepat produksi lakaselebih awal yaitu dalam waktu dua hari, namunaktivitasnya masih lebih rendah dibandingkandengan kontrol pada inkubasi lebih lanjut.Lakase dari Omphalina sp. juga dapatdiproduksi pada medium yang mengandung2% TKKS dan aktivitasnya mencapai0,38 U/mL yang diinkubasi dalam suhu ruangselama 10 hari. Pemurnian parsial pada kolomSephacryl S-200 HR menghasilkan rendemensebesar 58,23% dengan kemurnian dua kalinya.Aktivitas lakase optimum pada pH 4,5 dantetap stabil setelah pemanasan selama 30 menitpada suhu ruang hingga 50 o C dan menuruntajam pada suhu 60 o C. Lakase Omphalina sp.menghasilkan nilai K M dan V maks masing-masing sebesar 0,15 mM dan 0,56 U/mL.


Sign in / Sign up

Export Citation Format

Share Document