Potato dextrose broth

Adapted media for the microbial strains potato dextrose broth (PDB, Difco) used at half-strength (12 g/L for filamentous fungi supplemented with antibiotics) and Poor broth (PB, 1% bactotryptone, 0.9% NaCl w/v, pH 7.4) if bacterial strains for activity screening during isolation. 

Each Pit microbe was initially grown in 6 different nutrient broths as both shake (7 day) and still culture (21 day) to assess what growth conditions yielded the maximum biological activity. Each microbe was grown in a 100 mL nutrient broth in 250 mL Erlenmeyer flasks. The media used included PDB (DIFCO potato dextrose broth) PDBH+ ( PDB acidified to pH 2.5 by the drop wise addition of sterile 1.0 M H2SO4) Pit II (filter sterilized Berkeley Pit surface water added to an equivolume sterile solution of 5 g/L soytone and 5 g/L glucose) TSB (DIFCO tryptic soy broth) TSBH+ (TSB acidified to pH 2.5) and Myc (DIFCO mycological broth). 

Note YPG media (0.2% yeast extract, 1.0% peptone, and 2.0% glucose) MSM, molasses salt medium (0.2% yeast extract and molasses as carbon source) PDB, potato dextrose broth (20% potato extract and 2% dextrose) YM media (0.3% yeast extract, 0.3% malt extract, 0.5% polypeptone, and 1.0% glucose) AIF, alkali insoluble fraction DA, degree of acetylation DDA, degree of deacetylation DP, degree of polymerization M, molecular weight SmF, submerged fermentation SSF, solid-state fermentation. 

PDY (Potato Dextrose Yeast broth) PDY broth is made in exactly the same manner except the agar is omitted. Mason jars are filled half way with the hot or cool liquid. 

PDY (Potato Dextrose Yeast) Agar the filtered, extracted broth from boiling 300 grams of sliced potatoes in 1 liter of water for 1 hour20gramsagar... 

Media are prepared to defined formulations using requisite amounts of appropriate chemicals. Many of the more commonly used media, such as nutrient broth, tryptone soya broth, malt agar, and potato dextrose agar, are available in pre-mixed dehydrated form from various specialist suppliers. Any components of media that are heat-sensitive must be added to the remainder of the medium after it has been heat-sterilized by autoclaving this is normally done by syringing in these particular components as concentrated aqueous solutions through disposable sterile filter units available from various specialist suppliers. 

Potato dextrose agar Tween-80 Tryptone WL-nutrient agar WL-differential agar Wort agar Yeast carbon base Yeast extract YM agar YM broth... 

Erlenmeyer flasks (500 ml) containing medium (250 ml) made from malt extract (30 l), glucose (20 g/1) and peptone (3 g/l), were inoculated with spores of the fiingi previously grown on solid potato dextrose agar. The culture broth was grown without shaking at 24 C for 21 days. 

PDCB was prepared by suspending cut-up unpeeled potatoes (100 g L ) and carrots (10 g L ) in purified water and heated to boiling in a microwave oven for 5-10 min. Dextrose (d-(- -)-glucose) was added (30 g L ). The medium was sterilized by autoclaving for 20 min at 121 °C and then decanting off the broth. The broth is clear to slightly opalescent and yellowish in colour. No pH adjustment was made. 

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