Week 11: Healing people and planet with protists and viruses

Zooxanthellae

Photosynthetic protists

Zooxanthellae have symbiotic relationships with…

marine invertebrates

Most common zooxanthellae genus

Symbiodibium

Zooxanthellae motile stage

Free living with flagella for movement through water column

Zooxanthellae coccoid stage

Intracellular symbionts, no flagells

Corals

Marine invertebrates; calcium carbonate skeletons that make coral reefs

Coral reefs are… that support…

biodiversity hotspots, support ~25% of all marine species

Roles of reef ecosystems

__ from storms and erosion

Fisheries and __

T____

Sources of novel _

Coastal protection, food security, Tourism and recreation, pharmaceuticals

How are reefs indicators of ocean health?

They’re sensitive to environmental changes

Mutualistic symbiosis: Zooxanthellae live inside coral _, provide coral with up to 90% of its __ via _

cells, energy needs, photosynthesis

Mutualistic symbiosis: Coral provides __ and compounds necessary for _

‘safe home’, photosynthesis

Coral bleaching

Corals stressed by environmental changes expel zooxanthellae

Coral bleaching can be induced by…

climate change and ocean warming, pollution and sedimentation, ocean acidification

Corals can recover from bleaching if favourable conditions return, but long-term stressful conditions makes them…

vulnerable to disease and death

Assisted evolution: __ to accelerate rate of _ occuring __ when speed of climate change _ natural rate of coral adaptation.

Active intervention, naturally, evolutionary processes, outpaces

Assisted evolution 1

Identify resilient strains with bettter thermal tolerance

Assisted evolution 2

‘Force’ evolution of strains via culturing in lab under increasing temperatures

Assisted evolution 3

Reintroduction of heat-tolerance zooxanthellae to corals

Assisted evolution 4

Promote natural spread in the ecosystem

Challenge with assisted evolution:

Cultures sometimes showing _ to increased temp. _ these when placed in __, indicating. lack of ___.

adaptations, lose, cooler temp, acclimation and adaptation

Challenge with assisted evolution:

Thermal tolerance is not always…

‘transferred’ to the corals

Challenge with assisted evolution:

Heat-tolerant strains may not…

perform well under other stressors (e.g. acidification, pollution)

Challenge with assisted evolution:

Difficult to apply at large reef scales…

reintroduction and spread are slow and resource-intensive

Challenge with assisted evolution:

In modified zooxanthellae, there is potential for…

reduced genetic diversity or unintended traits

Challenge with assisted evolution:

Requies ___ to asses effectiveness and __

long-term tracking, ecological impact

Biofuels

Renewable enregy sources derived from biomass; used as alternatives to fossil fuels

Algal biofuels

Some of their energy from photosynthesis is stored as oils, can be harvested as a fuel source

Need for biofuels:

Burning fossil fuels releases __, contributing to…

greenhouse gases, global warming and climate change

Need for biofuels:

Combustion of fossil fuels releases __ contributing to _ and _

harmful pollutants, smog, acid rain

Need for biofuels:

Producing biofuels domestically reduces country’s…

dependence on foreign oil and gas supplies

Steps of making algal biofuel

Cultivation, harvesting, oil extraction, conversion

Algal biofuel: cultivation

Algae are cultivated in large volumes (often in ponds or bioreactors), grow via photosynthesis

Algal biofuel: harvesting

Algae are harvested, high water content removes via filtration or centrifugation

Algal biofuel: oil extraction

Energy-rich oils in algae extracted by breaking down cell structures

Algal biofuel: conversion

Extracted oils converted into usable fuels via transtesterification or distillation and cracking

Algae cultivation: Algae need…

Sunlight, CO₂, water, essential nutrients like nitrogen and phosphorus

Algae cultiavtion: open systems

Large ponds or open tanks, easier and cheaper to operate, more susceptible to evaporation and contamination

Algae cultivation: closed systems

Photobioreactors (tubular/flat panels allowing light penetration), more controlled parameters, more efficient, reduced space requirements, more expensive

A commonly used algae for biofuel production is __.

_cellular, freshwater _ algae.

Has a high _ content and __, making it very suitable for biofuel production.

Can grow in _ carbon-rich habitats, including _, supporting its treatment and _ recovery.

Scenedesmus sp., Uni, green, lipid, biomass yield, diverse, wastewater, nutrient

Advantages of algal biofuels:

Algae have potential for significantly higher ____ compared to other biofuel crops.

yields per unit of land

Advantages of algal biofuels:

Algae convert _ from atmosphere, offering potential pathway to ____

CO₂, reduce greenhouse gas emissions

Advantages of algal biofuels:

Demand for __ can be met using ___

high water, low-quality sources

Advantages of algal biofuels:

Algae can be grown in…

a wide variety of locations, incl. non-arable land

Advantages of algal biofuels:

Biomass can be used to…

produce multiple types of biofuels

Challenges and obstacles of algal biofuels:

Current technologies make production of algal biofuels…

expensive compared to fossil fuels

Challenges and obstacles of algal biofuels:

Harvesting and oil extraction can be…

energy-intensive, concerns about overall net energy gain

Challenges and obstacles of algal biofuels:

Significant improvements needed in… for more…

upstream and downstream phases of production, efficiency and cost-effectiveness

Challenges and obstacles of algal biofuels:

Some research suggests algal biodiesel may emit…

more carbon during productoin than fossil fuels

Challenges and obstacles of algal biofuels:

Still difficult to…

produce at large scales

Consequences of increase in bacterial strains resistant to antibiotics

Infections become difficult/impossible to treat, longer hospital stays, complex treatments, greater expenses, increased risk fo sever illness, disability, death form common infections, procedures like surgery become more dangerous

Bacteriophage: Virus which ___ within bacteria. Has high _, able to disrupt bacterial _, __ with bacteria.

infects and replicates, specificity, biofilms, co-evolve

Phage therapy

Use of bacteriphages as a treatment for bacterial infections

Phage therapy 1

Screening phage libraries or environmental samples for specific phage to target specific bacteria

Phage therapy 2

Purify and formulate selected phages into therapeutic product

Phage therapy 3

Administering treatment via topical, oral, IV, aerosol

Advantages of phage therapy over antibiotics

High specificity, can attack biofilms, multiply in body while infection is present, can evolve to overcome resistance mechanisms, can treat resistant infections or as complement to antibiotics (enhancing effectiveness)

Challenges of phage therapy

Each phage specific to certain strain, highly personal, lack of large-scale trials and regulatory pathways, bacteria can develop resistance

Increasing effectiveness of phage therapy

Use alongide antibiotics, use ‘cocktails’, genetically manipulate phage

Using phage alongside antibiotics

Resistance mechanisms are different (bacteria unlikely to overcome both), acquiring resistance to one usually leads to increased sensitivity to the other

Genetically manipulating phage

Broaden host range, boost lytic activity, evade bacteria defences