title: Heat treatment of wheat straw by immersion in hot water decreases mushroom yield in Pleurotus ostreatus.
abstract: BACKGROUND
  The oyster mushroom, Pleurotus ostreatus, is cultivated worldwide. It is one of the most appreciated mushrooms due to its high nutritional value. Immersion of the substrate in hot water is one of the most popular and worldwide treatment used for mushroom farmers. It is cheap and easy to implement.
  
  
  OBJECTIVE
  To compare the yields obtained during mushroom production of P. ostreatus using different pre-treatments (immersion in hot water, sterilization by steam and the use of fungicide) to determine if they influence mushroom crop.
  
  
  METHODS
  Four different treatments of substrate (wheat straw) were carried out: (i) immersion in hot water (IHW); (ii) steam sterilization; (iii) chemical; and (iv) untreated. The residual water from the IHW treatment was used to evaluate the mycelium growth and the production of P. ostreatus.
  
  
  RESULTS
  Carbendazim treatment produced highest yields (BE: 106.93%) while IHW produced the lowest BE with 75.83%. Sugars, N, P, K and Ca were found in residual water of IHW treatment. The residual water increased the mycelium growth but did not increase yields.
  
  
  CONCLUSIONS
  We have proved that IHW treatment of substrate reduced yields at least 20% when compared with other straw treatments such as steam, chemical or untreated wheat straw. Nutrients like sugars, proteins and minerals were found in the residual water extract which is the resultant water where the immersion treatment is carried out. The loss of these nutrients would be the cause of yield decrease. Alternative methods to the use of IHW as treatment of the substrate should be considered to reduce economical loss.
authors.affiliation: Instituto de Investigaciones Biotecnológicas, IIB-INTECH UNSAM-CONICET, Chascomús, Buenos Aires, Argentina.
authors.forename: Santiago
authors.initials: S
authors.lastname: Jaramillo Mejía
authors.forename: Edgardo
authors.initials: E
authors.lastname: Albertó
mesh_terms: D000383:Agriculture / Q000379:methods*; D001562:Benzimidazoles / Q000494:pharmacology; D002219:Carbamates / Q000494:pharmacology; D002241:Carbohydrates / Q000032:analysis / Q000494:pharmacology; D002412:Cations / Q000032:analysis / Q000494:pharmacology; D005659:Fungicides, Industrial / Q000494:pharmacology; D006358:Hot Temperature; D007101:Immersion; D061352:Pasteurization / Q000379:methods*; D010940:Plant Proteins / Q000032:analysis / Q000494:pharmacology; D018547:Plant Stems / Q000737:chemistry / Q000382:microbiology*; D020076:Pleurotus / Q000187:drug effects / Q000254:growth & development*; D013242:Sterilization / Q000379:methods*; D014908:Triticum; D062065:Wastewater / Q000737:chemistry
chemical_list: D001562:Benzimidazoles; D002219:Carbamates; D002241:Carbohydrates; D002412:Cations; D005659:Fungicides, Industrial; D010940:Plant Proteins; D062065:Wastewater; C006698:carbendazim