fundamentals of biological processes

8/2/2019 Fundamentals of Biological Processes

1/22

Fundamentals of

BiologicalProcesses


2/22

Object Of Presentation

To introduce the important aspectsinvolved in microbial metabolism.

To introduce the principal organismsresponsible for wastewatertreatment.


3/22

Why Biological treatment?

10 x 106L Chemicals

8 x 106L Xenobiotic

1 x 106

L Recalcitrant

0.4 x 106 traded at over 50 tonnes

per year


4/22

Objective of biological treatment:

Coagulate and remove the non-settleable colloidal solids .

Stabilize the organic matter.

Reduce the organic matter.

Remove the nutrients.

In short, stabilize organic matter:

convert organic matter tononbiodegradable form so that it doesnot exert oxygen demand.


5/22

Microbes

Virtually every environmental niche

Extremes of pH and salinity

Extremes of temperature and pressure Without air (Anaerobic)

Growth on many chemical substrates

Attached to surfaces in biofilms Geothermal vents and subterranean

deposits


6/22

MICROBIALMETABOLISM

General nutritional requirements -:

CARBON SUBSTRATE (org. or inorg.)

ELECTRON DONOR

ENERGY SOURCE

Need for molecular oxygen.

Basic elements required-C,O ,N,H, P,S

Inorganic elements: K,Mg,Ca,Fe,Na,Cl


7/22

Role of microbes

-

SINGLEBACTERIUM

2.0mORGANIC

POLLUTANT

AND NUTRIENTS

(C,P,N,O,Fe,S)

GROWTH - CELL DIVISION

INCREASE IN BIOMASS(assimilation)

CO2

evolved

(dissimilation)

O2consumption

Controlled release of energy

Slow Burning!


8/22

Basic growth


9/22

Types of microbes

Depending on the energy and carbon source AUTOTROPHS: microbes requiring inorganic

carbonaceous compounds. HETEROTROPHS: microbes requiring organic

compounds . PHOTOTROPHS: microbes consuming light as energy

source . CHEMOTROPHS: microbes obtaining energy from

oxidation of org. or inorg. Compounds. ORGANOTROPHS: organic compounds as source of

electron. LITHOTROPHS: inorganic compounds as source of

electron. E.g. nitrifying bacteria is an example ofchemolitho-

autotrophs.


10/22

CLASSIFICATION OFMICROORGANISMS

PHOTOAUTOTROPHIC

CHEMOAUTOTROPHIC

AUTOTROPHIC HETEROTROPIC

CHEMOHETEROTROPHIC

PHOTOHETEROTROPHIC

CO2

Organic carbon

INORGANIC ORGANIC

OXIDATIONREDUCTION REACTION


11/22

Microbes

By relationship to oxygen

obligate aerobes: need oxygen, use it asterminal electron acceptor

obligate anaerobes: cannot grow in thepresence of oxygen

facultative anaerobes: under certain

conditions can grow in the absence ofoxygen


12/22

Microbe shrinking

Numbers of ribosomes in a cell are tightly linked togrowth rate: E. coli fast ~ 1,000 E. coli slow ~ 10-100When cell lacks nutrients, it eats its own ribosomesto survive (shrinks) because

ribosomes make up much of all volume.


13/22

Energetics


14/22

Central Metabolism Basically the working in a microbial cell is

more or less like a tower by which energygeneration through a various combination ofsubstrates is detected.

EMP (Glycolysis and TCA /Krebs Cycle).C6

2C3(2ATP,2 NADH,2 pyruvate)(2NADH &

2CO2) 2C2 TCA 4CO2, 6NADH

,2ATP & 2FADH2


15/22

Net Energy

Most of the usable energy is beingconverted to-:

1. 10 Molecules of NADH (two fromglycolysis, two from the transitionstage, and six from the Krebs cycle)

2. 2 molecules of FADH23. 4 Molecules of ATP (net gain is only

of 2ATPs)


16/22

Energetic Contd.

Rg = rate of bacterial growth,mass/unit volume time

Y = max. yield coefficient, mg/mg. rsu = Substrate utilization rate.

Rg= -Yrsu

rsu=-mXS / Y(ks+S)


17/22

Energetics Energetic considerations Yield (Y): how much biomass/specific substrate

can be made Theoretically need 35 mmol ATP/g all biomass,

so 1 mol ATP . 30 g cells. Experimental: Streptococcus faecalis Yglucose = 22 g/mol 2 ATP / glucose

Zymomonas mobilis Yglucose = 8.3 g /mol .1 ATP / glucose ~ 10 g biomass/mol ATP


18/22

Energetics Cont.

/


19/22

Important organisms in w/wtreatment

Bacteria Fungi

Nemotodes


20/22

Important organisms in w/wtreatment

Algae

Important organisms in w w


21/22

Important organisms in w wtreatment

Protozoa Rotifers, ciliates,crustaceans

Stentor Celops

Paramecium


22/22

THANK YOU

fundamentals of biological processes

Documents