It can be measured by measuring the density of spores (number of

spores per unit volume) with Hemocytometer. The counting chamber of Hemocytometer is simply a ruled slide with a supported glass cover that held a definite volume of cell suspension. All The Best.

-AKM

Hemocytometer is the best method

Try counting by using Neaubar's chamber. 

Thank You all for adding answer to my question .I will try using the different protocol that has been already discussed by various researcher in the above discussion. 

Are you sure that your Rhizopus strain forms spores during growth in broth? You mean in submerged culture? Normally the sporangiospores are only formed on aerial hyphae after growth on solid medium.

With respect to determining the titer, the technique depends on your needs. A counting chamber is nice for determining the mere number of spores, but if you need numbers for spores that are able to germinate, you will have to plate reasonable dilutions on solid medium and count the number of developing colonies. This is easy, but requires constant observation, as Rhizopus does not form compact colonies,

Good luck.

Thank you very much Sir for enriching my knowledge through your vast experience on working on fungus.You were right in saying that Rhizopus strain do not form spores while doing broth culture .As this is my first experience of working on fungus.

  Sir can you please help me to find most  appropriate method for counting the spore of Rhizopus  strain. As for now i am doing slant culture and incubating it for 7 days at 4 degree centigrade and than harvesting it through 1% tween 20 solution and than counting the same on hemocytometer  on per ml basis of tween 20 solution.

I am waiting for your kind response soon.

Easy question, easy answer:

A good approach (not the only one) is

1.  to inoculate the medium in a Petri dish with either spores or, as traditional mycologists often do, with a square-cm (roughly) of grown mycelium from a previous plate.

2. to incubate the plate at room temperature (20-25 degrees) for approximately 8 days. During this time Rhizopus has covered the plate completely, has formed sporangia with many sporangiospores that are mature and able to germinate (normally some 80 % germination rate).

3. to wash the spores from the plate with a 10 ml glas pipette and 10 ml of your Tween solution (maybe you should go down to 0.1 %; many people just use sterile water.)

4. to store the suspension in the refrigerator.

5. to determine the spore concentration in a Neubauer chamber or similar (as you already do).

Don't hesitate to ask for additional details if necessary.

Good luck, jw.

Thank you very much Sir for your kind response .I will let you know if i face any problem in my further research work .

... and ideally also about success? May I ask: Did you isolate Rhizopus from fish, and is this the reason for the 4 degree slants?

Off course Sir not only problem i will also share my success . 

Actually i have got the pure strain   of Fungi Rhizopus oryzae from NCIM (http://www.ncl-india.org/files/NCIM/OrderCultures.aspx?menuid=ql5).As this fungi grow very fast on PDA at room temperature  so to slow down the growth , after 24 hr incubation at room temperature i store them at 4 degree and use it after 7 day of culture for inoculation on the substrate .

OK. I understand now. Are you sure that, under these conditions, the spores are able to germinate with a good rate? I never checked that.

Yes sir it is growing very nicely over slant in 1-2 days only and then it start forming spores afterwards i checked it on slant as well as on plate.

Dear Sir Johannes Wöstemeyer,

I want to use Rhizopus oryzae and A. niger spore suspensions from liquid medium for solid state fermentation. I need to know a clear way to harvest spores, count them and make a suspension.

Ok, a problem that is not too difficult to solve for solid media (see below). For liquid shaken cultures you will certainly not be able to obtain spores in reasonabe amounts. These fungi (especially Rhizopus) do not like to form their typical spores during submerged growth. If you just grow them on liquid medium without shaking, you will obtain similar results as on solidified medium. If you mean that, you could - in principle - just shake the complete culture, thereby producing a spore suspension that can be pipetted off or simply filtered through paper. From then on, you can count the spores as below.

. i. You grow the fungi on solid medium (Petri dish or 100 ml Erlenmeyer with 20 ml solid medium) for one week. ii. You add 10 ml sterile water and agitate carefully with the tip of a 10 ml pipet in order to get the spores in suspension. iii. You transfer the spore suspension in a tube. iv. If you wish, you may wash the agar surface with additional 5 ml water. v. You count the spore titre in a hemocytometer. vi. You check for viability and germination rate by plating 0.2 ml aliquots of a suitable dilution on plates and count colonies after germination. That's it.

Thank you so much, sir! I have both PDA and liquid cultures. I will go for PDA culture. I hope the protocol you motioned works for A. niger too.